Mid Rivers Mall Drive/I-70 & Route 79/I-70 Interchange Study

Transcription

1 Mid Rivers Mall Drive/I-70 & Route 79/I-70 Interchange Study Prepared for: City of St. Peters One St. Peters Center Boulevard St. Peters, Missouri 63376

2 TABLE OF CONTENTS Introduction... 5 Study Area... 5 Existing Conditions Analysis... 6 Existing Traffic Volumes... 6 Exhibit 1: Existing Traffic Volumes... 8 Existing Traffic Conditions... 9 I 70 Corridor... 9 Mid Rivers Mall Drive Route Existing Bridges Existing Operating Conditions Safety Analysis Mid Rivers Mall Drive I 70 at Mid Rivers Mall Drive Interchange Mid Rivers Mall Drive Corridor Route I 70 at Route 79 Interchange Route 79/Salt Lick Road Corridor Traffic Forecasts I 70 Traffic Forecasts Mid Rivers Mall Drive Traffic Forecasts Route 79 Traffic Forecasts Exhibit 2: 2030 No Build Traffic Volumes 2030 No Build Analysis No Build Analysis I Mid Rivers Mall Drive Route Alternative Development I 70 Alternatives Mid Rivers Mall Drive Interchange Alternatives Diverging Diamond with Eastbound I 70 to Veterans Memorial Parkway Bonus Ramp Tight Diamond with Texas U Turn Alternatives Considered but Eliminated due to Traffic Operations Concerns Single Point Urban Interchange Page 1

3 Folded Diamond Continuous Flow Intersection with Relocated Loop Ramp Relocated Loop Ramp Roundabouts Mid Rivers Mall Drive North Outer Road Alternatives Route 79 Interchange Alternatives Dual Lane Southbound to Eastbound Loop Ramp and Restriping of Southbound Route 79 Approaching I Continuous Northbound Green T Intersection Eastbound Right turn Lane at Veterans Memorial Parkway/Salt Lick Road Intersection Addition of a Right turn Lane at the Eastbound I 70 Exit Ramp; Continuing on Southbound Route 79 to Veterans Memorial Parkway Alternatives Considered but Eliminated due to Cost Concerns Alternatives Considered but Eliminated due to Right of Way Concerns Alternatives Considered but Eliminated due to Traffic Operations/Safety Concerns Build Analysis I 70 / Mid Rivers Mall Drive Interchange I 70 / Route 79 Interchange I 70 Mainline Alternative 1 Fifth Lane I Alternative 2 North Outer Road Pedestrian and Bicycle Access Drainage Traffic Control Right of Way Utilities Cost Analysis Meetings and Discussion Schedule Conclusion Exhibit 3: 2030 Forecasted Traffic Volumes Five Lane Freeway Alternative Exhibit 4: 2030 Forecasted Traffic Volumes Outer Road Alternative Page 2

4 LIST OF FIGURES Mid Rivers Mall Drive/I-70 & Route 79/I-70 Interchanges Study Figure 1: Study Area... 5 Figure 2: Mid Rivers Mall Drive/I-70 Interchange Existing Conditions Location Map Figure 3: Westbound I-70 between Route 370 and Mid Rivers Mall Drive (PM Peak Period) Figure 4: Route 79/I-70 Interchange Existing Conditions Location Map Figure 5: Southbound Route 79 to I-70 Eastbound Loop Ramp (AM Peak Hour) Figure 6: Northbound Salt Lick Road to I-70 Eastbound On-Ramp (AM Peak Hour) Figure 7: Mid Rivers Mall Drive Interchange Corridor Crash by Year and Corridor Figure 8: I-70 at Mid Rivers Mall Drive Interchange Crashes by Type Figure 9: Mid Rivers Mall Drive Corridor Crashes by Location Figure 10: Mid Rivers Mall Drive Corridor Crashes by Type Figure 11: Route 79 Corridor Crash by Year and Corridor Figure 12: I-70 at Route 79 Interchange Crashes by Type Figure 13: Route 79 Corridor Crashes by Location Figure 14: Route 79/ Salt Lick Road Corridor Crashes by Type Figure 15: I-70 Historical and Forecasted Traffic Counts Figure 16: Executive Center Parkway Area Figure 17: Developable Area along Mid Rivers Mall Drive, North of I Figure 18: Future Land Uses per St. Peters and O Fallon s Comprehensive Plans Figure 19: No Build 2030 Westbound I-70 at Mid Rivers Mall Drive (PM) Figure 20: No Build 2030 Westbound I-70 at Missouri Route 370 (PM) Figure 21: No Build 2030 at Mid Rivers Mall Drive (PM) Figure 22: No Build 2030 at Mid Rivers Mall Drive and the North Outer Road (PM) Figure 23: No Build 2030 at State Route 79 (AM) Figure 24: No Build 2030 at State Route 79 (PM) Figure 25: Diverging Diamond Interchange Figure 26: Tight Diamond Interchange with Texas U-Turn Figure 27: Single Point Urban Interchange Figure 28: Folded Diamond Interchange Figure 29: Continuous Flow Intersection with Relocated Loop Ramp Figure 30: Relocated Loop Ramp Figure 31: Roundabouts Figure 32: Route 79/I-70 Interchange with North Outer Road Option Figure 33: Mid Rivers Mall Drive/I-70 Interchange with North Outer Road Option Figure 34: Build 2030 at Mid Rivers Mall Drive (AM Peak Hour) Figure 35: Build 2030 at State Route 79 (AM Peak Hour) Figure 36: Route 79/I-70 Interchange with I-70 Fifth Lane Option Figure 37: Mid Rivers Mall Drive/I-70 Interchange with I-70 Fifth Lane Option Figure 38: Mid Rivers Mall Drive/I-70 Interchange Stage 1 Traffic Control Figure 39: Route 79/I-70 Interchange with Stage 1 Traffic Control Figure 40: Mid Rivers Mall Drive Interchange with Stage 2 Traffic Control Figure 41: Route 79/I-70 Interchange with Stage 2 Traffic Control Figure 42: Mid Rivers Mall Drive Interchange with Stage 3 Traffic Control Figure 43: Route 79/I-70 Interchange with Stage 3 Traffic Control Figure 44: Mid Rivers Mall Drive/I-70 Interchange with Stage 4 Traffic Control Figure 45: Route 79/I-70 Interchange with Stage 4 Traffic Control Page 3

5 Figure 46: North Outer Road Typical Sections Figure 47: I-70 Fifth Lane Typical Sections Figure 48: Mid Rivers Mall Drive Preliminary Alternatives Cost Summary Figure 49: Design-Bid-Build Schedule Figure 50: Design-Build Schedule LIST OF TABLES Table 1: Intersection Level of Service Thresholds Table 2: Freeway Level of Service Criteria Table 3: Existing Intersection Operating Conditions Mid Rivers Mall Drive Corridor (Synchro) Table 4: Existing Intersection Operating Conditions Mid Rivers Mall Drive Corridor (VISSIM) Table 5: Existing Intersection Operating Conditions Route 79/Salt Lick Road Corridor (Synchro) Table 6: Existing Intersection Operating Conditions Route 79/Salt Lick Road Corridor (VISSIM) Table 7: Existing Conditions Freeway Analysis Results (HCS+) Table 8: Existing Conditions Freeway Analysis Results (VISSIM) Table 9: Fatal Crashes on I-70 at Route 79 Interchange Table 10: 2030 No Build Intersection Operating Conditions Mid Rivers Mall Drive Corridor (Synchro) Table 11: 2030 No Build Intersection Operating Conditions Mid Rivers Mall Drive Corridor (VISSIM) Table 12: 2030 No Build Intersection Operating Conditions Route 79/Salt Lick Road Corridor (Synchro) 51 Table 13: 2030 No Build Intersection Operating Conditions Route 79/Salt Lick Road Corridor (VISSIM). 52 Table 14: 2030 No Build Conditions Freeway Analysis Results (HCS+) Table 15: 2030 No Build Conditions Freeway Analysis Results (VISSIM) Table 16: 2030 Build Intersection Operating Conditions Mid Rivers Mall Drive Corridor (Synchro) Table 17: 2030 Build Intersection Operating Conditions Mid Rivers Mall Drive Corridor (VISSIM) Table 18: 2030 Build Intersection Operating Conditions Route 79/Salt Lick Road Corridor (Synchro) Table 19: 2030 Build Intersection Operating Conditions Route 79/Salt Lick Road Corridor (VISSIM) Table 20: 2030 Build Conditions Freeway Analysis Results Alternative 1 (5 Lane I-70) (HCS+) Table 21: 2030 Build Conditions Freeway Analysis Results Alternative 1 (5 Lane I-70) (VISSIM) Table 22: 2030 Build Conditions Freeway Analysis Results Alternative 2 (Outer Roads) (HCS+) Table 23: 2030 Build Conditions Freeway Analysis Results Alternative 2 (Outer Roads) (VISSIM) Table 24: Right-of-Way Takings Table 25: Mid Rivers Mall Drive and Route 79 at Interstate 70 Fifth Lane Conceptual Cost Estimate Table 26: Mid Rivers Mall Drive and Route 79 at Interstate 70 North Outer Road with Future Fifth Lane Conceptual Cost Estimate Page 4

6 Introduction The Mid Rivers Mall Drive/I-70 Interchange is a busy interchange located in the City of St. Peters in St. Charles County, Missouri. It is one of the main points of ingress and egress into the City of St. Peters. The Route 79/I-70 Interchange is another heavily travelled interchange located 1 ½ miles west of the Mid Rivers Mall Drive/I-70 Interchange. It is also located in St. Peters in St. Charles County. Both interchanges are located along a heavily travelled, often congested portion of I-70. The interchanges require proposed changes to alleviate congestion along I-70 and the interchanges themselves. Horner & Shifrin, Inc. and Crawford, Bunte, and Brammeier (CBB) have completed a study to improve the transportation system in this area. The study proposes improvements at three locations - Mid Rivers Mall Drive/I-70 Interchange, Route 79/I-70 Interchange, and I-70 between Mid Rivers Mall Drive and Route 79 to alleviate the congestion along I-70 and improve traffic flow at the interchanges. Study Area The study area, depicted in Figure 1, is located in the City of St. Peters in St. Charles County, Missouri along I-70, approximately 25 miles west of downtown St. Louis. Specifically, the study area includes: Figure 1: Study Area Interstate 70 mainline from approximately 1 mile east of Mid Rivers Mall Drive to 1 mile west of Route 79. I-70/ Mid Rivers Mall Drive Interchange I-70/ Route 79/Salt Lick Road Interchange Mid Rivers Mall Drive intersection with: Page 5

7 o I-70 North Outer Road/Main Street; o I-70 Westbound Ramps; o I-70 Eastbound Ramps/Veterans Memorial Parkway; o Mid Rivers Mall Access; o Suemandy Road; o Mid Rivers Center Access; and o McMenamy Road. North Outer Road & North Spencer Loop Veterans Memorial Parkway & Mid Rivers Mall Right-In/Right-Out intersection Route 79/Salt Lick Road intersection with: o I-70 Westbound Ramps; o I-70 Eastbound Ramps; o Veterans Memorial Parkway; o Dierberg s Right-In/Right-Out; o Janis Ann Drive Existing Conditions Analysis As a first step in identifying traffic flow needs and opportunities within the study area, it is critical to identify and document existing issues and constraints. This section of the technical report summarizes the existing traffic constraints and issues in the study area. Existing Traffic Volumes An extensive data collection effort was completed to properly analyze the existing conditions for the study area. Turning movement counts and queue observations were collected for the weekday AM and PM peak periods (7-9 AM and 4-6 PM) at the following locations: o Route 79 at Turner Boulevard/Terra Lane o Route 79 at I-70 Westbound Ramps o Route 79 at I-70 Eastbound Ramps o Salt Lick Road at Veterans Memorial Parkway o Salt Lick Road at Dierberg s right-in/right-out access drive o Salt Lick Road at Janis Ann Drive Saturday midday peak period (11 AM - 2 PM) turning movement counts and queue observations were also collected at the following locations in addition to AM and PM data collection efforts: o Mid Rivers Mall Drive at the I-70 North Outer Road/Main Street o Mid Rivers Mall Drive at the I-70 Westbound Ramps o Mid Rivers Mall Drive at the I-70 Eastbound Ramps/Veterans Memorial Parkway o Mid Rivers Mall Drive at Mid Rivers Mall Access o Mid Rivers Mall Drive at Suemandy Drive o Mid Rivers Mall Drive at Mid Rivers Center Access/Barnes & Noble o Mid Rivers Mall Drive at McMenamy Road o I-70 North Outer Road at Spencer Loop Road North Page 6

8 The manual counts were augmented with automatic machine counts that obtained daily volumes along the following corridors: o All Ramps at I-70 and Mid Rivers Mall Drive Interchange o Mid Rivers Mall Drive north of I-70 North Outer Road/Main Street o Mid Rivers Mall Drive south of I-70 Eastbound Ramps/Veterans Memorial Parkway o Mid Rivers Mall Drive south of McMenamy Road o Veterans Memorial Parkway west of Mid Rivers Mall Drive o I-70 North Outer Road east of Mid Rivers Mall Drive o Main Street west of Mid Rivers Mall Drive o All Ramps at I-70 and Route 79/Salt Lick Road Interchange o Route 79 north of I-70 o Salt Lick Road south of Veterans Memorial Parkway Existing traffic volumes are displayed on Exhibit 1. From these counts, it was determined that the overall peak hours of traffic flow occur between 7:30 a.m. and 8:30 a.m. in the morning, between 4:45 p.m. and 5:45 p.m. in the afternoon and between 11:45 a.m. and 12:45 p.m. during the Saturday peak period. Saturday data was only collected for Mid Rivers Mall Drive because the Saturday traffic related to the commercial development within the study area. Page 7

9 Mid Rivers Mall Drive 6,750 (4,900) <4,425> 600 (415) <450> 25 (25) <20> 50 (275) <90> 130 (350) <195> 350 (375) <360> 5 (15) <25> 20 (55) <80> 5 (45) <40> 15 (60) <100> 120 (155) <210> 15 (65) <110> 5 (5) <15> 55 (55) <95> 5 (55) <70> 25 (35) <5> 115 (80) <110> 90 (50) <60> 80 (405) <430> 5 (20) <30> 15 (135) <185> 100 (200) <220> 5 (85) <120> 50 (320) <315> 10 (40) <55> 5 (15) <20> 10 (80) <95> 35 (25) <5> 15 (10) <5> 30 (30) <5> 80 (165) <120> 760 (1,710) <1,595> 40 (65) <5> 40 (45) <85> 865 (1,805) <1,555> 15 (25) <60> 75 (165) <190> 855 (1,490) <1,275> 45 (105) <165> 35 (90) <80> 955 (1,580) <1,405> 70 (270) <535> 20 (15) <25> 35 (75) <90> 25 (10) <10> * No Saturday Analysis for Route 79/Salt Lick Road Corridor (10) <10> 150 (50) <45> Mall Access Suemandy Road Barnes & Noble McMenamy Road 85 (85) <90> 1,185 (1,130) <1,450> 70 (50) <5> 20 (40) <95> 1,290 (1,120) <1,380> 25 (75) <90> 15 (65) <100> 1,260 (935) <1,045> 80 (215) <385> 20 (35) <35> 1,410 (1,165) <1,325> 50 (90) <115> 255 (350) <415> 85 (30) <80> 150 (100) <95> North Outer Road Main Street 570 (1,100) <1,100> 340 (385) <430> 940 (525) <735> 650 (1,325) <1,265> 75 (150) <210> 180 (110) <125> 380 (450) <465> 410 (615) <755> 150 (95) <160> 500 (1,100) <1,080> 210 (350) <220> 305 (450) <425> 35 (125) <95> 90 (430) <165> 115 (220) <140> 80 (65) <65> Spencer Loop 650 (1,195) <1,240> 1,160 (3,125) <1,260> 850 (730) <900> 100 (50) <65> 225 (110) <85> 3,665 (7,565) <4,595> 325 (350) 150 (200) 205 (330) 3,055 (6,225) 2,000 (1,175) <975> 25 (175) <300> 1,370 (950) <1,110> 80 (75) <30> 5,125 (4,565) 845 (430) 605 (1,260) 80 (195) <240> 180 (225) 970 (1,175) <1,345> 100 (45) 80 (180) 485 (870) 300 (780) 55 (130) 1,150 (910) 75 (25) 1,110 (705) 95 (335) 45 (60) Turner Boulevard Terra Lane 785 (1,650) 3,635 (7,545) <4,370> 6,790 (5,270) <4,840> 1,000 (500) 375 (505) 295 (105) 515 (1,115) Veterans Memorial Parkway 5 (10) 180 (250) 40 (85) 30 (40) 205 (200) 465 (1,220) 15 (20) 5 (5) 5 (5) 60 (50) 1,165 (715) 15 (25) 105 (220) 405 (1,090) Dierbergs 15 (120) 75 (60) Janis Ann Drive (825) <795> 5 (10) 110 (100) 90 (170) 1,055 (630) 25 (35) 15 (90) 5 (10) 10 (30) 4,750 (3,725) <3,450> 2,505 (4,440) <3,335> ,900 (4,170) <3,525> Veterans Memorial Pkwy Mall Access n.t.s. 10 (50) 380 (1,110) 30 (50) Legend = Existing Traffic Signal XX = AM Peak Hour Traffic (7:30-8:30 AM) (XX) = PM Peak Hour Traffic (4:45-5:45 PM) <XX> = Saturday Peak Hour Traffic (11:45 AM- 12:45 PM) Salt Lick Road Exhibit 1: Existing Traffic Volumes I-70/Mid Rivers Mall Drive Interchange Study St. Peters, Missouri Job# CBB 1/04/11 Crawford, Bunte, Brammeier Traffic and Transportation Engineers

10 Existing Traffic Conditions I-70 Corridor Interstate 70 extends from Cove Fort, Utah to Baltimore, Maryland and provides a key connection for transcontinental traffic and provides local connections from western Missouri and suburbs to St. Louis area, including downtown St. Louis. Consequently, I-70 is a heavily used corridor with through traffic heading across the state and commuter traffic throughout the study area, providing connections for businesses and residences in the western part of the metropolitan area. I-70 also provides important connections to some of the St. Louis region s major commuter routes: Route 370, I-270, and Route 94. In the study area, I-70 mostly has four through lanes in each direction. Westbound I-70 between Missouri Route K and Mid Rivers Mall Drive frequently breaks down during the afternoon peak hours due to lack of adequate capacity, resulting in significant delays. This condition is worsened by the occurrence of minor incidents. In 2007, East-West Gateway Council of Governments forecasted in its report titled The St. Charles County Transportation Plan 2030 that conditions on I-70 between Route 79 and Route 370 will continue to worsen and deteriorate to a stop-start mode during daily operations (Level of Service F). The recently completed auxiliary lane improvements and truck lane restrictions are described as intermediate solutions to underlying capacity issues associated with the terminus of Route 79 and Route 370 at I-70. In 1996, Bucher, Willis, & Ratliff Corporation recommended construction of one way frontage roads as a long term solution for congestion on I-70 in their report titled I-70 Congestion Mitigation Study, Route 40/61 to Route I-270. A segment of this one way system was constructed south of I-70 between Mid Rivers Mall Drive and Suemandy Road; however, this concept has not been implemented at other locations on the corridor. Within the study area, the segment along I-70 between the Mid Rivers Mall Drive and Route 79 interchanges has four through lanes in both directions and an eastbound auxiliary lane between the interchanges. Additionally, east of Mid Rivers Mall Drive interchange two westbound auxiliary lanes are provided connecting to Route 370. In the morning peak period, it is common for eastbound I-70 to be congested from Missouri Route K to Route 79, a distance of approximately three miles. In the afternoon peak period, there is a major bottleneck on westbound I-70 at Mid Rivers Mall Drive. Three lanes of traffic from Route 370 merge with three lanes of traffic on I-70, but only four lanes continue on westbound I-70 past Mid Rivers Mall Drive. The flow of traffic in those four lanes is further impacted by entering traffic from Mid Rivers Mall Drive, which is afforded short distances to merge onto I-70. On a typical weekday afternoon, westbound I-70 is queued from west of Mid Rivers Mall Drive to Route 370. At times this queue can reach Cave Springs Road, a distance of 3 miles. As described earlier, westbound I-70 breaks down between Route 79 and Route 370 resulting from inadequate capacity west of Mid Rivers Mall Drive. Additionally, there is a downstream capacity constraint on I-70 further west of this study area at T.R.Hughes Boulevard. On a typical weekday, it does not impact traffic operations in the study area. However, congestion from this downstream bottleneck occasionally impacts and worsens traffic flow in the study area. Page 9

11 Figure 2 shows the typical afternoon congestion on westbound I-70 between Route 370 and Mid Rivers Mall Drive. Figure 2: Westbound I-70 between Route 370 and Mid Rivers Mall Drive (PM Peak Period) Mid Rivers Mall Drive The existing Mid Rivers Mall Drive/I-70 Interchange is a diamond interchange with loop ramps located in the northeast and southwest quadrants. Mid Rivers Mall Drive (MRMD) is one of the main entry and exit points into the center of the City of St. Peters. Mid Rivers Mall Drive continues north and south of the intersection at I-70. Outer roads are located to the north and south of the interchange. North Outer Road and Main Street intersect Mid Rivers Mall Drive to the north of the interchange and Veterans Memorial Parkway intersects Mid Rivers Mall Drive to the south. An entrance/exit to Mid Rivers Mall is 500 ft south of the Veterans Memorial Parkway/Mid Rivers Mall Drive intersection. Figure 3 shows the existing roads along Mid Rivers Mall Drive. One of the primary issues for northbound traffic on Mid Rivers Mall Drive is that all movements onto I-70 are right-turn movements, which forces the majority of traffic into the right lane. This problem is exacerbated by the fact that the Mid Rivers Mall (and a significant amount of associated retail development) is located on the east side of the road, also drawing traffic into the right lane. The resulting poor utilization of traffic using the left lanes results in traffic queues in the right lane to Suemandy Drive from the I-70 interchange. At times this traffic queues as far south as Mexico Road. Another issue is the close spacing between the North Outer Road and westbound I-70 ramp intersections. This spacing results in poor signal progression and creates difficult maneuvers for trucks, which frequent the truck-stop in the northwest quadrant of the interchange. Page 10

12 NORTH OUTER ROAD MID RIVERS MALL DRIVE, HIGHWAY 79, AND COLLECTOR-DISTRIBUTOR AT INTERSTATE 70 HORNER & SHIFRIN, INC. NORFOLK SOUTHERN RAILROAD DARDENNE CREEK GATTY STREET CHURCH STREET MAIN STREET INTERSTATE 70 VETERANS MEMORIAL PARKWAY SUEMANDY ROAD MID RIVERS MALL DRIVE FIGURE 3

13 During the PM peak hour, the mixing of commuter and retail oriented traffic results in heavy traffic movements onto and off of the interstate. Of specific concern is the heavy westbound off-ramp traffic, which queues far onto the ramp. Additionally, eastbound right-turn traffic from Main Street/ North Outer Road to the interchange backs up into old town St. Peters frequently during the PM peak hour. Saturday traffic is heavy along Mid Rivers Mall Drive due to the concentration of commercial uses just south of I-70. During peak shopping periods, delays at the signalized intersections can become heavy and vehicles exiting eastbound I-70 at Mid Rivers Mall Drive frequently queue onto the interstate. As stated previously, on a typical weekday afternoon, westbound I-70 is queued from west of Mid Rivers Mall Drive to Route 370. This results from three lanes of traffic from Missouri Route 370 merging with three lanes of traffic on I-70, but only four lanes continuing on westbound I-70 past Mid Rivers Mall Drive. Route 79 The existing Route 79/I-70 Interchange is a diamond interchange with a loop ramp located in the southwest quadrant. Route 79 continues north from the interchange to Hannibal, Missouri. Salt Lick Road runs south of the interchange into the City of St. Peters. Veterans Memorial Parkway is an outer road located on the south side of the interchange and ends at the intersection with Salt Lick Road. Figure 4 displays the Route 79/I-70 Interchange configuration. As with northbound traffic at the Mid Rivers Mall Drive interchange, one of the primary issues along southbound Highway 79 is that all movements onto I-70 are right-turn movements, which forces the majority of traffic into the right lane. The right lane routinely queues back to the on-ramp from Terra Lane (North Service Road) and beyond. The distance from Terra Lane southbound entrance ramp to the I-70 westbound entrance ramp is not sufficient which exacerbates the weaving issues for traffic approaching the interchange. Specifically, southbound Route 79 to eastbound I-70 queues beyond the ramps to East Terra Lane during the AM peak hour, as shown in Figure 5. Similarly, the northbound Salt Lick Road queues past Janis Ann Drive during the AM peak period as shown in Figure 6. This queue occurs due to vehicles stopping at Veterans Memorial Parkway, it is not related to I-70 congestion. In the PM peak hour, the I-70 eastbound and westbound ramp terminal intersections at Route 79 experience congestion due to the heavy amounts of traffic trying to use those intersections. Also, the eastbound I-70 ramp terminal operates under two-way stop control and vehicles must find gaps on Route 79 to merge onto the roadway, which are infrequent since there is a heavy through traffic volume on Route 79. This issue is prevalent all day, not just the peak periods of high traffic volumes. Page 12

14 DARDENNE CREEK ROUTE 79 AND INTERSTATE 70 EXISTING LAYOUT HORNER & SHIFRIN, INC. TERRA LANE ROUTE 79 DARDENNE CREEK BRIDGE VETERANS MEMORIAL PKWY INTERSTATE 70 SALT LICK ROAD JANIS ANN DR FIGURE 4

15 RI/RO Entrance Figure 5: Southbound Route 79 to I-70 Eastbound Loop Ramp (AM Peak Hour) Figure 6: Northbound Salt Lick Road to I-70 Eastbound On-Ramp (AM Peak Hour) There are several issues at the Veterans Memorial Parkway intersection with Route 79. First, the signal is not coordinated with adjacent signals. Eastbound traffic on Veterans Memorial Parkway that is destined to eastbound I-70 crowds the left/through lane, resulting in periodic instances of long queues and poor utilization of the inner left-turn lane. Due to the absence of dedicated right-turn lane, the presence of rightturning vehicles worsens this congestion. Existing Bridges Both interchanges contain bridges which span over I-70. Per the typical bridge section plan from MoDOT (dated July 11, 1997), the existing bridge on Mid Rivers Mall Drive over I-70 is 97 ft wide from face of barrier to face of barrier and 99 ft - 8 inches wide from the back of east barrier to back of west barrier. The existing bridge over I-70 at the Route 79 Interchange is 80 ft wide from face of barrier to face of barrier and 82 ft - 8 inches wide from back of barrier on the east side of the bridge to the back of barrier on the west side of the bridge. The Mid Rivers Mall Drive Bridge contains four lanes with two lanes in each direction. The Route 79 Bridge carries two northbound lanes and three southbound lanes with a 10 ft outside shoulders and no median. Page 14

16 Existing Operating Conditions Mid Rivers Mall Drive/I-70 & Route 79/I-70 Interchanges Study A detailed capacity analysis was undertaken to determine the anticipated roadway operating conditions for the existing, no-build, and build conditions. Various tools were used to evaluate the operating conditions of the different scenarios. SYNCHRO, VISSIM, and the Highway Capacity Software (HCS+) traffic evaluation packages were used in the analysis to capitalize on the strengths of each tool and to compare the results of various packages for further verification. VISSIM was used to evaluate all aspects of the study area, including freeways, ramps, and all intersection types. VISSIM is a micro-simulation traffic flow model that specializes in the analysis of complex transportation systems. It is especially useful for analyzing freeways due to its sophisticated driver behavior algorithms that accurately reflect lane changing and car following maneuvers. The analysis of freeway conditions on I-70 using VISSIM was augmented with evaluations using the Highway Capacity Software, which applies deterministic methods to identify freeway levels of service based upon analysis of specific freeway segments. Synchro was used to analyze signalized and unsignalized intersections. Synchro is similar to the Highway Capacity Software in that the underlying traffic flow models are analytical. However, Synchro is recognized as the most widely-used tool in the traffic engineering field for analyzing and optimizing traffic flows at signalized intersections. Operating conditions were graded in accordance with six levels of traffic service (Level A "Free Flow to Level F "Fully Saturated") established by the Highway Capacity Manual, last updated in 2000 by the Transportation Research Board. Levels of service (LOS) are measures of traffic flow which consider speed, delay, traffic interruptions, safety, driver comfort, and convenience. Level C, which is normally used for design, represents a roadway with volumes ranging from 70% to 80% of its capacity. Level D is generally considered acceptable for peak periods in urban and suburban areas. Several Measures of Effectiveness (MOE) were used in this evaluation including: LOS, volume to capacity ratios (v/c), vehicular delay, density, travel speed, and queue lengths. LOS is directly related to control delay. At signalized intersections, the LOS criteria differ from that at unsignalized intersections primarily because different transportation facilities create different driver expectations. The expectation is that a signalized intersection is designed to carry higher traffic volumes and, consequently, may experience greater delay than an unsignalized intersection. Table 1 summarizes the LOS thresholds used in the analysis for intersections. Typically LOS D is considered acceptable in urban areas for both freeways and arterial roadways. Table 1: Intersection Level of Service Thresholds Control Delay per Vehicle (seconds/vehicle) Level of Service (LOS) Signalized Intersections/Roundabouts Unsignalized Intersections A < B > > C > > D > > E > > F > 80 > 50 Page 15

17 In addition to LOS, v/c ratios provide important measures to describe an intersection s operations. Intersection movements can have acceptable LOS (D or better) yet still have unacceptably high v/c ratios. In general, v/c ratios around 0.9 result in occasional queuing and cycle failure, v/c ratios between 0.9 and 1.0 result in frequent queuing and cycle failure, and v/c ratios over 1.0 result in general failure of the movement. Therefore, it is important to consider v/c ratios in addition to LOS and vehicular delay when evaluating an intersection s operations. The mainline I-70 operating conditions analysis was performed using VISSIM and HCS+. Both analysis techniques used density as an MOE to determine LOS along a freeway. Although speed is a major indicator of service quality to drivers, freedom to maneuver within the traffic stream and proximity to other vehicles, as measured by the density of the traffic stream, are equally noticeable concerns. Density increases as flow increases up to capacity, resulting in an MOE that is sensitive to a broad range of flows. For these reasons, density is the parameter used to define LOS for the freeway and ramp sections, as shown in Table 2. Level of Service Freeway Weaving Segment Density (pc/mi/ln)* Table 2: Freeway Level of Service Criteria Merging and Diverging Segment Density (pc/mi/ln)* Basic Freeway Segment Density (pc/mi/ln)* A B > > > C > > > D > > > E > > 35 > F > 43 Demand exceeds capacity > 45 * pc/mi/ln = passenger cars per mile per lane The existing intersection operations analysis results from SYNCHRO and VISSIM for the Mid Rivers Mall Drive corridor are shown in Tables 3 and 4 for AM, PM and Saturday midday peak hours. Tables 5 and 6 are the existing intersection operations analysis results from SYNCHRO and VISSIM for the Route 79/Salt Lick Road corridor for the AM and PM peak hours. The highlighted areas of the tables signify intersections or roadway segments of concern. Specifically red highlighting denotes LOS F, v/c over 1.0 or queues greater than 750 feet and yellow highlighting denotes LOS E, v/c between or queues between feet. The existing freeway operations analysis results from HCS+ and VISSIM are summarized in Tables 7 and 8. For the most part, Tables 3 through 6 show relatively acceptable traffic operations at the study intersections. However, as stated earlier, the existing traffic constraints and congestion along northbound Mid Rivers Mall Drive and southbound Route 79 is a result of poor lane utilization of the left through lanes. The resulting queues and poor delays are not captured in the Synchro MOE tables because of Synchro s inability to accurately model this behavior. Additionally, delays resulting in queue spilling back to the adjacent intersections are not captured in VISSIM because of closely-spaced intersections and the associated node structure. However, the long queues at these intersections are captured in both the Page 16

18 SYNCHRO and VISSIM tables, especially along Mid Rivers Mall Drive for the PM and Saturday peak periods. Likewise Tables 7 and 8 show relatively acceptable freeway operations, with the exception of westbound I- 70 during the PM peak hour. The magnitude of the capacity failures is not truly captured in HCS+ due to the fact that the freeway is significantly constrained. The traffic counts are a measure of the traffic capacity, and are not representative of the demand. However, Table 8 (showing the VISSIM output) does accurately reflect delays and speeds that are seen in the field. Page 17

19 Synchro Intersection/Movement Mid Rivers Mall Drive/I-70 & Route 79/I-70 Interchanges Study Table 3: Existing Intersection Operating Conditions Mid Rivers Mall Drive Corridor (Synchro) AM Peak Hour (7:30 8:30) PM Peak Hour (4:45 5:45) SAT Peak Hour (11:45 12:45) Max. 95 LOS Delay th % Max. 95 LOS Delay th % Max. 95 LOS Delay th % V/C Queue V/C Queue V/C Queue Mid Rivers Mall Drive & North Outer Road/Main Street Eastbound Main Street C (T) C (T) B (T) Westbound North Outer Road C (L) D (L) D (L) Northbound Mid Rivers Mall Dr. B (L) C (L) B (L) Southbound Mid Rivers Mall Dr. C (L) D (T) D (T) Overall Intersection C C C Mid Rivers Mall Drive & I-70 Westbound Off-Ramp Westbound WB Entrance Ramp C (L) C (L) D (L) Northbound Mid Rivers Mall Dr. A (T) A (T) A (T) Southbound Mid Rivers Mall Dr. A (T) B (T) B (T) Overall Intersection B B C Mid Rivers Mall Drive & I-70 Eastbound Exit Ramp/Veterans Memorial Parkway Eastbound I-70 EB Exit Ramp C (T) D (R) E (R) Northbound Mid Rivers Mall Dr. B (R) B (T) C (T) Southbound Mid Rivers Mall Dr. A (T) B (T) B (L) Overall Intersection B C C Mid Rivers Mall Drive & Mid Rivers Mall Eastbound Mid Rivers Mall D (T) D (T) D (T) Westbound Mid Rivers Mall B (T) C (T) C (T) Northbound Mid Rivers Mall Dr. A (T) B (T) B (T) Southbound Mid Rivers Mall Dr. B (T) C (T) C (T) Overall Intersection A C C Page 18

20 Continue Table 3: Existing Intersection Operating Conditions Mid Rivers Mall Drive Corridor (Synchro) Mid Rivers Mall Drive & Suemandy Road Eastbound Suemandy Road D (L) D (L) D (L) Westbound Suemandy Road C (L) D (L) D (L) Northbound Mid Rivers Mall Dr. B (T) B (T) B (T) Southbound Mid Rivers Mall Dr. C (T) D (T) C (T) Overall Intersection B C C Mid Rivers Mall Drive & Barnes Noble Entrance Eastbound Barnes Noble Entrance D (L) D (L) D (L) Westbound Barnes Noble Entrance D (R) D (T) D (T) Northbound Mid Rivers Mall Dr. A (T) A (T) B (T) Southbound Mid Rivers Mall Dr. A (T) A (T) A (T) Overall Intersection A A B Mid Rivers Mall Drive & McMenamy Road Eastbound McMenamy Road C (L) D (L) D (L) Westbound McMenamy Road C (T) C (L) B (L) Northbound Mid Rivers Mall Dr. B (T) B (T) A (T) Southbound Mid Rivers Mall Dr. A (T) A (T) A (T) Overall Intersection B B A North Outer Road & North Spencer Loop Eastbound North Outer Road A (T) A (T) A (T) Westbound North Outer Road B (T) B (T) A (T) Southbound N. Spencer Loop A (L) B (L) A (L) Overall Intersection A B A Veterans Memorial Parkway & Mid Rivers Mall Right-In/Right-Out Eastbound Right-In A (R) A (R) A (R) Northbound Right-Out C (R) C (R) C (R) Page 19

21 Table 4: Existing Intersection Operating Conditions Mid Rivers Mall Drive Corridor (VISSIM) AM Peak Hour (7:30 8:30) PM Peak Hour (4:45 5:45) SAT Peak Hour (11:45 12:45) VISSIM Ave. Max Ave. Max Ave. Max Intersection/Movement LOS Delay LOS Delay LOS Delay Queue Queue Queue Queue Queue Queue Mid Rivers Mall Drive & North Outer Road/Main Street Eastbound Main Street C B B Westbound North Outer Road C D C Northbound Mid Rivers Mall Dr. A A A Southbound Mid Rivers Mall Dr. D D D Overall Intersection B C B Mid Rivers Mall Drive & I-70 Westbound Off-Ramp Westbound WB Entrance Ramp C C D Northbound Mid Rivers Mall Dr. A A A Southbound Mid Rivers Mall Dr. A B B Overall Intersection B B C Mid Rivers Mall Drive & I-70 Eastbound Exit Ramp/Veterans Memorial Parkway Eastbound I-70 EB Exit Ramp C C D Northbound Mid Rivers Mall Dr. A B B Southbound Mid Rivers Mall Dr. A A B Overall Intersection B B C Mid Rivers Mall Drive & Mid Rivers Mall Eastbound Mid Rivers Mall D D D Westbound Mid Rivers Mall C C C Northbound Mid Rivers Mall Dr. B B B Southbound Mid Rivers Mall Dr. A B C Overall Intersection A C C Page 20

22 Continue Table 4: Existing Intersection Operating Conditions Mid Rivers Mall Drive Corridor (VISSIM) Mid Rivers Mall Drive & Suemandy Road Eastbound Suemandy Road D D D Westbound Suemandy Road C D D Northbound Mid Rivers Mall Dr. B B B Southbound Mid Rivers Mall Dr. B B B Overall Intersection B C C Mid Rivers Mall Drive & Barnes Noble Entrance Eastbound Barnes Noble Entrance D C D Westbound Barnes Noble Entrance C D D Northbound Mid Rivers Mall Dr. A A B Southbound Mid Rivers Mall Dr. A A A Overall Intersection A A B Mid Rivers Mall Drive & McMenamy Road Eastbound McMenamy Road C D C Westbound McMenamy Road D D D Northbound Mid Rivers Mall Dr. A B B Southbound Mid Rivers Mall Dr. A A A Overall Intersection A A A North Outer Road & North Spencer Loop Eastbound North Outer Road A A A Westbound North Outer Road A A A Southbound N. Spencer Loop A A A Overall Intersection A A A Veterans Memorial Parkway & Mid Rivers Mall Right-In/Right-Out Eastbound Right-In A A A Northbound Right-Out C C D Overall Intersection A A B Page 21

23 Synchro Intersection/Movement Mid Rivers Mall Drive/I-70 & Route 79/I-70 Interchanges Study Table 5: Existing Intersection Operating Conditions Route 79/Salt Lick Road Corridor (Synchro) AM Peak Hour (7:30 8:30) PM Peak Hour (4:45 5:45) SAT Peak Hour (11:45 12:45) Max. 95 LOS Delay th % Max. 95 LOS Delay th % Max. 95 LOS Delay th % V/C Queue V/C Queue V/C Queue Route 79 & I-70 Westbound Off-Ramp Westbound I-70 WB Exit Ramp B (L) B (L) Northbound Route 79 A (T) C (T) Southbound Route 79 B (T) C (T) Overall Intersection B C Route 79 & I-70 Eastbound Off-Ramp Eastbound Left-Turn E F Eastbound Right-Turn E F Salt Lick Road & Veterans Memorial Parkway Eastbound Veterans D (L) D (L) Westbound Veterans C (T) C (T) Northbound Salt Lick B (T) B (T) Southbound Salt Lick B (T) C (T) Overall Intersection B C Salt Lick Road & Dierberg s Right-In/Right-Out Eastbound Right-Turn A B Southbound Right-Turn A A Salt Lick Road & Janis Ann Drive Eastbound Janis Ann D (L) D (L) Westbound Janis Ann C (T) C (L) Northbound Salt Lick B (T) B (T) Southbound Salt Lick A (T) B (T) Overall Intersection B B Page 22

24 VISSIM Intersection/Movement Mid Rivers Mall Drive/I-70 & Route 79/I-70 Interchanges Study Table 6: Existing Intersection Operating Conditions Route 79/Salt Lick Road Corridor (VISSIM) AM Peak Hour (7:30 8:30) PM Peak Hour (4:45 5:45) SAT Peak Hour (11:45 12:45) Ave. Max Ave. Max Ave. Max LOS Delay LOS Delay LOS Delay Queue Queue Queue Queue Queue Queue Route 79 & I-70 Westbound Off-Ramp Westbound I-70 WB Off-Ramp B B Northbound Route 79 C C Southbound Route 79 B C Overall Intersection B C Route 79 & I-70 Eastbound Off-Ramp Eastbound Left-Turn C C Eastbound Right-Turn A B Salt Lick Road & Veterans Memorial Parkway Eastbound Veterans Memorial Pkwy. C C Westbound Veterans Memorial Pkwy. C B Northbound Salt Lick Road A A Southbound Salt Lick Road A A Overall Intersection A B Salt Lick Road & Dierberg s Right-In/Right-Out Eastbound Right-Turn A A Southbound Right-Turn A A Salt Lick Road & Janis Ann Drive Eastbound Janis Ann Drive D C Westbound Janis Ann Drive C C Northbound Salt Lick Road A A Southbound Salt Lick Road A B Overall Intersection B B Page 23

25 HCS+ SECTION DIRECTION Table 7: Existing Conditions Freeway Analysis Results (HCS+) TYPE LOS AM Peak Hour Density (pc/mi/ln)* Avg. Speed (mph)** LOS PM Peak Hour Density (pc/mi/ln)* Avg. Speed (mph)** LOS Saturday Mid Day Peak Hour Density (pc/mi/ln)* West of Route 79 EB Freeway C C Between Route 79 & Mid Rivers Mall Interchanges EB Freeway D C C Mid Rivers Mall Loop On-Ramp EB Merge D C B East of Mid Rivers Mall Loop Ramp EB Freeway D C B Between Mid Rivers Mall & Route 370 Interchanges EB Freeway D C B Between Route 370 & Mid Rivers Mall Interchanges WB Freeway B C B Mid Rivers Mall Loop On-Ramp WB Merge B D B Mid Rivers Mall On-Ramp WB Merge B C B Between Mid Rivers Mall & Route 79 Interchanges WB Freeway C E C Route 79 Off-Ramp WB Diverge A A Route 79 On-Ramp WB Merge B D West of Route 79 Interchange WB Freeway B D * pc/mi/ln = passenger cars per mile per lane ** mph = miles per hour Avg. Speed (mph)** Page 24

26 VISSIM SECTION Table 8: Existing Conditions Freeway Analysis Results (VISSIM) DIRECTION TYPE LOS AM Peak Hour Density (pc/mi/ln)* Avg. Speed (mph)** LOS Mid Rivers Mall Drive/I-70 & Route 79/I-70 Interchanges Study PM Peak Hour Density (pc/mi/ln)* Avg. Speed (mph)** LOS Saturday Mid Day Peak Hour Density (pc/mi/ln)* West of Route 79 EB Freeway C C Route 79 Off-Ramp EB Diverge C B Route 79 Loop On-Ramp EB Merge C B Route 79 On-Ramp EB Merge C B Between Route 79 & Mid Rivers Mall Interchanges EB Freeway C B B Mid Rivers Mall Off-Ramp EB Diverge C B B Mid Rivers Mall Loop On-Ramp EB Merge B B B East of Mid Rivers Mall Loop Ramp EB Freeway C B B Veteran Memorial Slip On-Ramp EB Merge C B B Between Mid Rivers Mall & Route 370 Interchanges EB Freeway C B B Between Route 370 & Mid Rivers Mall Interchanges WB Freeway A F B Mid Rivers Mall Off-Ramp WB Diverge A F B Mid Rivers Mall Loop On-Ramp WB Merge B F B Mid Rivers Mall On-Ramp WB Merge B F B Between Mid Rivers Mall & Route 79 Interchanges WB Freeway B F B Route 79 Off-Ramp WB Diverge B D Route 79 On-Ramp WB Merge A C West of Route 79 Interchange WB Freeway B D * pc/mi/ln = passenger cars per mile per lane ** mph = miles per hour Avg. Speed (mph)** Page 25

27 Safety Analysis As part of the study, a safety analysis was completed to identify high-hazard locations in the study corridor by calculating crash rates for the last five calendar years of available data for Mid Rivers Mall Drive corridor, Route 79/ Salt Lick Road corridor and I-70 within the study area. As part of the evaluation, safety deficiencies analyzed included: crash rates verse statewide rates (where available), high crash locations, and crash types, contributing factors, severity and trends. Mid Rivers Mall Drive The crash statistics for the years 2005 through 2009 were received from the Missouri Highway Patrol along Mid Rivers Mall Drive between the Westfield Mall Entrance and the North Outer Road/Main Street intersection and along I-70 within 1.0 mile east and 1.0 mile west of Mid Rivers Mall Drive interchange to determine any safety performance issues. During this time period, 317 crashes were reported on I-70 and 431 crashes reported on Mid Rivers Mall Drive. Overall, rear end crashes were the most prominent type of crash on each route, mostly due to congestion and heavy traffic areas. Figure 7 shows the total number of crashes by year for the Mid Rivers Mall Drive corridor and I-70 within the vicinity of Mid Rivers Mall Drive interchange as well as a combination of the two. There were 748 reported crashes in the five year time period. Specifically, 189, 142, 149, 158, and 110 crashes occurred in 2005, 2006, 2007, 2008, and 2009, respectively. As can be seen, the total crashes are fairly consistent over the five year period with a slight trend downward. I-70 at Mid Rivers Mall Drive Interchange The crash data received for the years 2005 through 2009 reported 317 total crashes within 1 mile each direction of Mid Rivers Mall Drive interchange. Of the 317 crashes, 69 reported injuries and zero fatalities. As a result I-70 had an injury crash rate of approximately 22%. A large majority (76% or more) of the crashed along I-70 occurred during the daylight, on dry pavement and on fair weather dry days. 89% of I-70 crashes occurred on fair weather days (clear or cloudy) 11% of I-70 crashes occurred on inclement weather days (rain, sleet, snow) 76% of I-70 crashes occurred on dry pavement 24% of I-70 crashes occurred on wet or snow covered pavement 77% of I-70 crashes occurred in the daylight 23% of I-70 crashes occurred in the dark As shown in Figure 8, rear ends were the most common crash type at 51%, followed by fixed object (16%), sideswipes (15%), angle (8%), other (5%), other-object (2.5%), overturned (1.5%), and animal/backing (1%). Page 26

28 Figure 7: Mid Rivers Mall Drive Interchange Corridor Crash by Year and Corridor Number of Crashes Total Crashes Mid Rivers Mall Drive 89 Crashes I-70 Crashes Year Figure 8: I-70 at Mid Rivers Mall Drive Interchange Crashes by Type Number of Crashes REAR END 51% FIXED OBJECT 16% SIDESWIPE 15% ANGLE 8% Type of Crash OTHER 5% OTHER-OJECT 2.5% OVERTURN 1.5% ANIMAL/BACKING 1% Page 27

29 Crash rate is a quantitative measure for reporting crashes on a roadway. The crash rate for a roadway segment, such as along I-70, is the ratio of the number of crashes per year to the average daily traffic (ADT) per mile and is reported as rate per 100 million vehicle miles (HMVM) for convenience. crash _ ratesegment = ( AADT )( no _ of 8 ( no._ of _ crashes)(10 ) days _ years)(365 )( length _ of year _ segment) The average crash rate over the 5 year analysis period for the segment of I-70 is 59.4 HMVM. This shows that the crash rate along the segment of I-70 is less than the statewide average for interstates (108.3 HMVM). The analysis of the crash data over the past 5 years along I-70 near Mid Rivers Mall Drive interchange indicates that rear end crashes are the most prominent type of crash, which is typical for a congested interstate corridor. Mid Rivers Mall Drive Corridor The crash data received for the years 2005 through 2009 reported 431 total crashes on Mid Rivers Mall Drive between the Westfield Mall Entrance to the North Outer Road. Of the 431 crashes, 73 reported injuries and zero fatalities. As a result, the study intersections along Mid Rivers Mall Drive had an injury crash rate of approximately 17%. A large majority (79% or more) of the crashes along the Mid Rivers Mall Drive corridor occurred during the daylight, on dry pavement and on fair weather dry days. 92% of I-70 crashes occurred on fair weather days (clear or cloudy) 8% of I-70 crashes occurred on bad weather days (rain, sleet, snow) 80% of I-70 crashes occurred on dry pavement 20% of I-70 crashes occurred on wet or snow covered pavement 79% of I-70 crashes occurred in the daylight 21% of I-70 crashes occurred in the dark Figure 9 shows the number of crashes and percentage of crashes by location. As can be seen, Veterans Memorial Parkway had the most crashes (198) comprising approximately 45% of the Mid Rivers Mall Drive corridor crashes. Page 28

30 Figure 9: Mid Rivers Mall Drive Corridor Crashes by Location NOR 70/MAIN; 73 Crashes; 17% I-70 INTERCHANGE; 50 Crashes; 12% WESTFIELD MALL; 110 Crashes; 26% VETERANS MEMORIAL PARKWAY; 198 Crashes; 45% Crash rates for intersection related crashes, such as Mid Rivers Mall Drive corridor, are the ratio of the number of annual crashes per million vehicles entering the location, reported as rate per million vehicles entering (MVE) for convenience. crash _ rate int er sec tion = 8 ( no._ of _ crashes)(10 ) days ( entering _ volume)( no._ of _ years)(365 ) year The crash rate for each intersection along Mid Rivers Mall Drive was found to be less than 2.1 MVE per intersection based on the collected data. Based on available data from 2004 through 2008, the average crash rate for Missouri state routes was 2.60 MVE. This shows that the crash rate for the intersections along Mid Rivers Mall Drive is lower than the crash rate for state highways. A high crash location is where the crash rate is in excess of 5.0 MVE. The crash rate for the intersections along the Mid Rivers Mall Drive corridor is approximately half the rate of high crash locations. As shown in Figure 10, angle crashes were the most common crash type along Mid Rivers Mall Drive with approximately 42%, followed by rear ends (37%), sideswipes (12%), fixed object (4%) and miscellaneous (5%). Miscellaneous crashes include back-in, head-on, overturn, animal, bicycle-pedestrian or other. Page 29

31 Figure 10: Mid Rivers Mall Drive Corridor Crashes by Type The analysis of the crash data over the past 5 years indicates that angle and rear end crashes are the most prominent type of crash along the Mid Rivers Mall Drive corridor, which is typical for signalized corridors. The crash rates are below the state average and well below the threshold for high crash locations. Route 79 Crash data was provided by the Missouri State Highway Patrol for 2005 through 2009 based on reported crashes in the Missouri Statewide Traffic Accident Records System (STARS). I-70 was analyzed within 1.0 mile east and 1.0 mile west of Route 79. The study area along Route 79/ Salt Lick Road included the area from East Terra Lane to Janis Ann Drive. Figure 11 shows the total number of crashes by year for each study corridor as well as a combination of the two. There were 700 reported crashes in the five years from 2005 to Specifically, 115, 139, 191, 141, and 114 crashes occurred in 2005, 2006, 2007, 2008, and 2009, respectively. As can be seen, a small spike occurred along I-70 in That spike appears to be due to an increase in rear end crashes on I-70 in Page 30

32 Figure 11: Route 79 Corridor Crash by Year and Corridor Total Crashes Number of Crashes I-70 Crashes MO 79 Crashes Year of Crash Of the total crashes reported in the study area, 536 property damage only (76.5%), 160 injury (22.9%), and 4 fatal (0.6%) crashes were reported. The four fatal crashes were further scrutinized in an attempt to develop trends or reveal geometric deficiencies, if any. One fatality occurred on southbound Route 79 at the westbound on/off ramps to I-70 and the other three fatalities were along I-70. Table 9 summarizes the fatalities in the study area. Page 31

33 No 1 2 Location SB Route 79 at I-70 Westbound On-Ramp WB I-70 east of Route 79 Off- Ramp 3 EB I-70 west of Route 79 4 EB I-70 west of Route 79 Table 9: Fatal crashes on I-70 at Route 79 Interchange Type of Accident Angle (NB LT & SB TH) Out of Control Pedestrian out of Vehicle Out of control Road Surface Conditions Dry Dry Dry Dry Light Conditions Dark-street lights off Daylight Dark-no streetlights Dark-no streetlights Other Southbound vehicle ran red light colliding with northbound left-turn, Inattention Speeding motorist attempting to exit, lost control, striking fixed object and ejected from motorcycle Broke down on inside shoulder on Interstate, motorist exited vehicle, struck by another vehicle in left lane of EB I-70 Speeding motorist attempting to exit, lost control, ran off road, struck fixed object, overturned and ejected person As can be seen, all the fatalities in the study area occurred with dry road conditions. One resulted from a vehicle failing to stop at a red light, one involved a motorist that was struck outside of their vehicle on the interstate and two were speeding motorist on the interstate attempting to make an exit and losing control and ultimately getting ejected. Three of the four occurred when it was dark. Based on the historical crash data, adding lighting along I-70 as well as at the Route 79 ramps may help reduce the crashes in the study area. I-70 at Route 79 Interchange The crash data received for the years 2005 through 2009 reported 536 total crashes within 1 mile, east or west, of Route 79. Of the 536 crashes, 121 reported injuries and three reported fatalities. As a result, I-70 had an injury crash rate of approximately 22.5% and a fatality crash rate of 0.5%. A large majority (78% or more) of the crashed along I-70 occurred during the daylight, on dry pavement and on fair weather days. 88% of I-70 crashes occurred on fair weather days (clear or cloudy) 12% of I-70 crashes occurred on inclement weather days (rain, sleet, snow) 78% of I-70 crashes occurred on dry pavement 22% of I-70 crashes occurred on wet or snow covered pavement 81% of I-70 crashes occurred in the daylight 19% of I-70 crashes occurred in the dark As shown in Figure 12, rear ends were the most common crash type at 60%, followed by fixed object (12%), sideswipes (10%), angle (9%), other (5%), and miscellaneous (4%). Miscellaneous crashes include overturn, animal, backing, pedestrian, and other fixed objects. Page 32

34 Figure 12: I-70 at Route 79 Interchange Crashes by Type Number of Crashes REAR END 60% FIXED OBJECT 12% SIDE-SWIPE 10% ANGLE 9% Types of Crashes OTHER 5% MISCELLANEOUS 4% The average crash rate over the 5 year analysis period for the study segment of I-70 is HMVM. Based on data from , the average crash rate for Missouri interstates was HMVM. This shows that the crash rate along the segment of I-70 is very near the statewide average for interstates. The analysis of the crash data over the past 5 years along I-70 near Route 79/ Salt Lick Road, it is evident that rear end crashes are the most prominent type of crash, which is typical for a congested interstate corridor. Although the only 19% of the crashes occurred during the dark, adding lighting may help reduce the number of crashes in the darkness. Route 79/Salt Lick Road Corridor The crash data received for the years 2005 through 2009 along Route 79/Salt Lick Road between East Terra Lane and Janis Ann Drive reported 164 total crashes. Of the 164 crashes, 39 reported injuries and one reported a fatality. As a result, the study intersections along Route 79 had an injury crash rate of approximately 23.8%. A large majority (71% or more) of the crashes along the Route 79 corridor occurred during the daylight, on dry pavement and on fair weather days. 86% of I-70 crashes occurred on fair weather days (clear or cloudy) 14% of I-70 crashes occurred on bad weather days (rain, sleet, snow) 76% of I-70 crashes occurred on dry pavement 24% of I-70 crashes occurred on wet or snow covered pavement 71% of I-70 crashes occurred in the daylight Page 33

35 29% of I-70 crashes occurred in the dark Figure 13 shows the number of crashes and percentage of crashes by location. As can be seen, the I-70 interchange area has the most crashes (93) comprising approximately 57% of the Route 79 corridor crashes. At the interchange, 68 crashes occurred at the north ramps (signalized), while 25 crashes occurred at the south ramp (unsignalized). Approximately 50% of the crashes at the north ramps involve vehicles traveling southbound and approximately half of the those accidents result in injuries. As a result, it is anticipated that the relatively high speed of Route 79, north of I-70, as well as the first stop along a divided highway may be contributing factors in the number of crashes at the north ramps. Figure 13: Route 79 Corridor Crashes by Location JANIS ANN; 22 Crashes; 13% NOR 70/TERRA; 16 Crashes; 10% SOR/Veterans Memorial Parkway; 33 Cashes; 20% I-70 Interchange; 93 Crashes; 57% The crash rates for each intersection along Route 79 were found to be less than 1.10 MVE per intersection based on the collected data. The average crash rate for Missouri state routes was 2.60 MVE from This shows that the crash rate for the intersections along Route 79 is much lower than the state rate. In general, a high crash location is where the crash rate excess 5.0 crashes per million vehicles entering. The intersections along the Route 79 corridor are not close to being considered high crash locations. As shown in Figure 14, rear end crashes were the most common crash type along Route 79 with approximately 43%, followed by angle (26%), sideswipes (14%), fixed object (9%), backing (3%), other (2%), animal (1%), head-on (1%) and overturned (1%). Page 34

36 Figure 14: Route 79/ Salt Lick Road Corridor Crashes by Type Number of Crashes REAR END 43% ANGLE 26% SIDE-SWIPE 14% FIXED OBJECT 9% BACKING 3% OTHER 2% Types of Crashes ANIMAL 1% HEAD ON 1% OVERTURN 1% The analysis of the crash data over the past 5 years along Route 79 near the I-70 interchange indicates that rear end and angle crashes are the most leading type of crash along the corridor, which is mostly typical for signalized corridors. The crash rates are below the state average and well below the threshold for high crash locations. Although approximately 29% of the crashes occurred in the dark, installing lighting along the corridor may decrease crashes. In addition, reducing the speed limit north of I-70 or improving driver awareness of the signal at the north ramp may decrease the number of crashes at the north ramps to the interchange. Page 35

37 Traffic Forecasts 2030 Traffic forecasts were developed for I-70, Mid Rivers Mall Drive, and Route 79. Several forecasting methodologies were used to provide quality control checks. Both trend analysis and land-use based procedures were used to ensure that forecasts are reasonable in the context of the surrounding land uses. The forecasting process considered: Output from the East-West Gateway and St. Charles County travel demand models; Historical trend analysis; and Likely changes to surrounding land use and proposed developments. I-70 Traffic Forecasts Traffic forecasts for I-70 were developed based on historical growth trends as well as output from both the East-West Gateway and St. Charles County travel demand models. As can be seen from Figure 15, the I- 70 corridor has experienced significant annual traffic growth from the mid-1970s. However, the rate of this growth is expected to slow due to the upgrading of US-40/I-64 between the Missouri River and I-70 to an interstate freeway, extension of MO 364 (Page Avenue) to I-64, and completion of Salt River Road. Interstate 70 Historical and Forecasted Traffic Counts Average Daily Traffic (ADT) MoDOT Historical Counts Study Projected 2030 ADT County Model ADT Output Year Figure 15: I-70 Historical and Forecasted Traffic Counts Page 36

38 The general forecasting methodology for I-70 assumed a 15 % growth in traffic volumes from 2010 to 2030, as is predicted by the St. Charles travel demand model. Mid Rivers Mall Drive Traffic Forecasts 2030 traffic forecasts along Mid Rivers Mall Drive were primarily developed using the St. Charles County Travel Demand Model. Since model inputs were a crucial driver of the resulting traffic output, the future land use inputs were compared to the County s model with the growth assumed by the City of St. Peters comprehensive plan to verify consistency. This comparison resulted in two inconsistencies between the model land use assumptions and the City s comprehensive plan. One pertains to the City s special use district along Executive Center Parkway area and the other pertains to the area adjacent to Mid Rivers Mall Drive north of I-70. In both areas, the County s model assumes less future development relative to the comprehensive plan and the City s growth expectations. In order to generate more conservative forecasts, the model inputs for these areas were modified to be more consistent with the City s plans for the future. Area along Executive Center Parkway: The County s model currently assumes 40,000 ft 2 of additional space over the next 20 years within an area bounded by I-70 on the north, Barnes-St. Peters Hospital to the east, Mexico Road on the south, and Spencer Road to the west, as illustrated in Figure 16 below. The model inputs were modified to assume that all vacant tracts along Executive Center Parkway would be fully developed by 2030, reflecting continued expansion of medical and office uses in the area. Specifically, office and commercial-type uses were assumed. Figure 16: Executive Center Parkway Area Area North of I-70: North of I-70, the County model inputs include only 70,000 ft 2 of development over the next 20 years. Approximately 270 acres of developable ground were estimated within the highlighted area shown in Figure 17. Thus, there is the potential for a much greater square footage yield to be realized in Page 37

39 the future. The subject area is bounded by levees on the north and west, existing development and the Norfolk Southern railroad on the south, and the City s Water Treatment/Recycling Facilities and detention basins on the east. Figure 17: Developable Area along Mid Rivers Mall Drive, North of I-70 The model was modified to assume that 50 percent of this area (about 135 acres) would be developed by To estimate how much square footage could be yielded, 10 percent was deducted to account for future infrastructure, such as the Salt River Road extension. A 20 percent coverage rate was then applied to the remaining acreage to reflect industrial development that is consistent with adjacent uses as well as the City s comprehensive plan. The resulting square footage yield amounted to 1,175,000 ft 2 of industrial development by Resulting 2010 to 2030 traffic growth: Mid Rivers Mall Drive North of I-70: o 200% increase in traffic o 2010 AADT of 4,000; 2030 AADT of 12,000 Mid Rivers Mall Drive South of I-70: o 10% increase in traffic o 2010 AADT of 42,000; 2030 AADT of 46,000 North Outer Road West of Mid Rivers Mall Drive (Main Street): o 20% decrease in traffic (due to the completion of Salt River Road between Route 370 and Route 79) Page 38

40 o 2010 AADT of 15,000; 2030 AADT of 12,000 North Outer Road East of Mid Rivers Mall Drive: o 22% increase in traffic o 2010 AADT of 9,000; 2030 AADT of 11,000 South Outer Road East of Mid Rivers Mall Drive (Veterans Memorial Parkway): o 33% increase in traffic o 2010 AADT of 6,000; 2030 AADT of 8,000 Route 79 Traffic Forecasts As with Mid Rivers Mall Drive, 2030 traffic forecasts along Route 79 were developed using the St. Charles County Travel Demand Model. Again, the future land use inputs were compared to the County s model with the growth assumed by the City s comprehensive plan to verify consistency. Inconsistencies were uncovered between the model s future land use assumptions and the acreage available for development north of Interstate 70. Specifically, it was found that the County s model did not account for increased industrial square footage north of the interchange. Both St. Peters and O Fallon s comprehensive plans designate the area outlined in red as shown in Figure 18 for future industrial development. Vacant parcels within the boundary amount to approximately 185 acres, furthermore, the City s comprehensive plan designates the residences along Brown Road (located in the interchange s northeast quadrant) as possible candidates for redevelopment as industrial uses. Combining both the residential area and vacant parcels yields approximately 225 acres of developable ground. For purposes of estimating how much square footage could develop, separate calculations were performed for areas north and south of the Norfolk Southern railway. It was reasoned that areas south of the railway are more likely to develop because they re well-served by existing infrastructure and proximity to Interstate 70. Areas north of the railway, which are more remote, would develop more slowly and several locations may need infrastructure upgrades in order to be viable. Half of the developable ground south of the railway was assumed would develop by Using the same 20% building coverage ratio applied for the Mid Rivers Mall Drive interchange study, 90 developable acres would yield 390,000 ft 2 of industrial development south of the railway. Page 39

41 79 79 I-70 I-70 Figure 18: Future Land Uses per St. Peters and O Fallon s Comprehensive Plans (industrial land uses depicted in gray) Resulting 2010 to 2030 traffic growth: Route 79 North of I-70: o 50% increase in traffic o 2010 AADT of 20,000; 2030 AADT of 30,000 Salt Lick Road South of I-70: o 22% increase in traffic o 2010 AADT of 22,000; 2030 AADT of 27,000 Veterans Memorial Parkway: o 33% increase in traffic o 2010 AADT of 6,000; 2030 AADT of 8, No Build traffic volumes are displayed on Exhibit 2. Saturday data was only collected for Mid Rivers Mall Drive because the Saturday traffic related to the commercial development within the study area. Page 40

42 Mid Rivers Mall Drive 7,850 (5,785) <5,280> 815 (595) <635> 50 (130) <65> 40 (205) <70> 245 (540) <440> 5 (15) <25> 25 (60) <85> 10 (50) <45> 25 (75) <145> 140 (180) <245> 15 (70) <115> 5 (10) <15> 60 (55) <100> 10 (60) <75> 30 (35) <5> 135 (100) <130> 95 (55) <65> 95 (455) <510> 5 (20) <30> 20 (140) <195> 120 (245) <250> 15 (110) <160> 55 (335) <335> 20 (45) <60> 5 (15) <20> 10 (85) <100> 40 (30) <5> 90 (195) <140> 845 (1,855) <1,795> 45 (70) <5> 45 (45) <90> 960 (1,975) <1,765> 20 (30) <65> 90 (185) <230> 955 (1,645) <1,470> 55 (135) <190> 35 (95) <85> 1,070 (1,775) <1,650> 85 (320) <600> 15 (15) <20> 215 (475) <360> 50 (40) <40> * No Saturday Analysis for Route 79/Salt Lick Road Corridor (10) <10> 110 (40) <35> 260 (315) <270> Mall Access Suemandy Road Barnes & Noble 20 (10) <5> 35 (30) <5> McMenamy Road 90 (90) <95> 1,300 (1,235) <1,625> 75 (55) <5> 20 (40) <100> 1,425 (1,245) <1,565> 30 (80) <95> 20 (70) <105> 1,400 (1,050) <1,215> 85 (225) <405> 25 (40) <40> 1,580 (1,340) <1,550> 55 (95) <120> 190 (260) <315> 375 (200) <280> 325 (245) <240> North Outer Road Main Street 650 (1,230) <1,290> 580 (530) <585> 1,050 (625) <855> 730 (1,465) <1,430> 140 (225) <280> 380 (220) <225> 515 (535) <575> 460 (725) <905> 310 (175) <250> 565 (1,235) <1,220> 290 (555) <370> 430 (775) <700> 40 (130) <100> 210 (645) <425> 125 (230) <150> 85 (70) <70> Spencer Loop 875 (1,410) <1,470> 1,570 (3,860) <1,515> 940 (815) <1,015> 105 (50) <70> 380 (275) <245> 4,415 (8,900) <5,395> 480 (480) 185 (275) 350 (545) 3,525 (7,205) 2,705 (1,660) <1,260> 35 (185) <315> 1,670 (1,200) <1,395> 125 (320) <210> 6,010 (5,195) 1,210 (655) 790 (1,595) 85 (210) <255> 320 (300) 1,355 (1,480) <1,705> 200 (65) 120 (235) 730 (1,340) 375 (965) 165 (270) 1,625 (1,285) 80 (30) 1,645 (1,060) 145 (495) 50 (65) 1,105 (2,305) 4,280 (8,965) <5,225> 8,140 (6,130) <5,760> 1,240 (580) 465 (690) 445 (160) 765 (1,660) Veterans Memorial Parkway 5 (10) 260 (340) 55 (105) 35 (40) 275 (295) 620 (1,510) 15 (25) 5 (5) 10 (5) 80 (65) 1,410 (890) 20 (30) 110 (230) 575 (1,390) Dierbergs RI/RO Turner Boulevard Terra Lane 20 (125) 85 (65) Janis Ann Drive (920) <930> 5 (10) 160 (175) 140 (245) 1,265 (745) 25 (40) 65 (165) 10 (10) 15 (35) 6,910 (4,970) <4,265> 5,145 (4,125) <4,020> 2,845 (5,040) <3,880> Veterans Memorial Pkwy Mall Access n.t.s. 65 (125) 495 (1,335) 35 (55) Legend = Existing Traffic Signal XX = AM Peak Hour Traffic (7:30-8:30 AM) (XX) = PM Peak Hour Traffic (4:45-5:45 PM) <XX> = Saturday Peak Hour Traffic (11:45 AM- 12:45 PM) Salt Lick Road Exhibit 2: 2030 Forecasted Traffic Volumes - No Build Network I-70/Mid Rivers Mall Drive Interchange Study St. Peters, Missouri Job# /04/11 CBB Crawford, Bunte, Brammeier Traffic and Transportation Engineers

43 2030 No Build Analysis In general, the problems that are being experienced in the study corridor are likely to worsen by 2030 if steps are not taken to improve operations and capacity. While some regional projects such as Phases 2 and 3 of Route 364 and Salt River Road between Route 370 and Route 79 will provide some relief to regional traffic, they will not fully address traffic issues in the study corridor. The following sections illustrate the anticipated 2030 conditions if improvements are not made to the Mid Rivers Mall Drive and Route 79 interchanges with I-70. I-70 Afternoon delays are expected to worsen on westbound I-70. The heavy through traffic and high volumes of traffic entering and exiting I-70 are expected to grow with increased local development. The westbound weaving movements between Mid Rivers Mall Drive and Route 79 will continue to saturate the right lanes of I-70. The resulting stop and go traffic would likely begin as early as 3:30 p.m. and continue beyond 6:00 p.m.. Typical queues would extend beyond Cave Springs Road and spill onto Route 370. Figures 19 and 20 provide VISSIM screenshots which illustrate typical queues expected between Route 370 and Mid Rivers Mall Drive and Route 370. Mid Rivers Mall Drive I-70 Figure 19: No Build 2030 Westbound I-70 at Mid Rivers Mall Drive (PM) Page 42

44 Mid Rivers Mall Drive I-70 WB ramp from Missouri Route 370 Mid Rivers Mall Drive Figure 20: No Build 2030 Westbound I-70 at Missouri Route 370 (PM) Mid Rivers Mall Drive is going to continue to be a major destination in St. Charles County due to the presence of Mid Rivers Mall and other major commercial retail centers in the surrounding area. The area will continue to attract a large number of trips, especially during peak shopping hours on Saturdays. In addition Mid Rivers Mall Drive will continue to be a heavily used commuter corridor. By 2030, northbound Mid Rivers Mall Drive would likely queue to Mexico Road on a regular basis. The short distances between adjacent signalized intersections will continue to inhibit lane changing and create difficulty for vehicles trying to access I-70, as shown in Figure 21. Moreover, the existing eastbound I-70 ramp/veterans Memorial Parkway delays would be likely to worsen, spilling back further onto I-70. Access to Mid Rivers Mall and surrounding retail uses would be constrained, limiting development potential. Page 43

45 I-70 Veterans Memorial Parkway Mall Access Mid Rivers Mall Drive Figure 21: No Build 2030 at Mid Rivers Mall Drive (PM) The traffic signals at Mid Rivers Mall Drive and the North Outer Road will operate over capacity by 2030, due in large part to its proximity to the I-70 westbound ramp terminal intersection, located just a few hundred feet to the south. Figure 22 shows a VISSIM screenshot of Mid Rivers Mall Drive at the North Outer Road. North Outer Road WB off ramp WB on ramp WB on ramp Mid Rivers Mall Drive Figure 22: No Build 2030 at Mid Rivers Mall Drive and the North Outer Road (PM) Route 79 By 2030, the I-70 eastbound and westbound ramp terminal intersections at Route 79 will experience failing movements during the PM peak period due to the heavy amounts of traffic trying to use those intersections. The northbound traffic movements will fail due to the long green phase given to accommodate traffic exiting westbound I-70. The unsignalized eastbound ramp terminal will become more Page 44

46 problematic from a capacity, and possibly safety standpoint. Figures 23 and 24 shows anticipated 2030 queues at the Route 79 at I-70 interchange. State Route 79 WB I-70 off ramp Figure 23: No Build 2030 at State Route 79 (AM) State Route 79 WB on ramp WB off ramp I-70 Figure 3: No Build 2030 at State Route 79 (PM) Page 45

47 The 2030 No Build intersection operations analysis results from SYNCHRO and VISSIM for the Mid Rivers Mall Drive corridor are shown in Tables 10 and 11 for AM, PM and Saturday midday peak hours. Tables 12 and 13 show the 2030 No Build intersection operations analysis results from SYNCHRO and VISSIM for the Route 79/Salt Lick Road corridor for the AM and PM peak hours. The highlighted areas of the tables signify intersections or roadway segments of concern. Specifically red highlighting denotes LOS F, v/c over 1.0 or queues greater than 750 feet and yellow highlighting denotes LOS E, v/c between or queues between feet. The 2030 No Build freeway operations analysis results from HCS+ and VISSIM are summarized in Tables 14 and 15. For the most part, Tables 10 through 13 shows degraded traffic operations at the study intersections as compared to the existing condition. Several intersections show high levels of saturation and delay. Moreover, long queues at these intersections are captured in both the SYNCHRO and VISSIM tables along both the Mid Rivers Mall Drive and Route 79 corridors. Likewise, Tables 14 and 15 show degraded freeway operations. One area of interest is the failing conditions along eastbound I-70 during the Saturday peak period. This is due to the failure of the eastbound Mid Rivers Mall Drive off-ramp, which queues back into and blocks mainline I-70 traffic in the VISSIM models. Page 46

48 Synchro Intersection/Movement Mid Rivers Mall Drive/I-70 & Route 79/I-70 Interchanges Study Table 10: 2030 No Build Intersection Operating Conditions Mid Rivers Mall Drive Corridor (Synchro) AM Peak Hour (7:30 8:30) PM Peak Hour (4:45 5:45) SAT Peak Hour (11:45 12:45) Max. 95 LOS Delay th % Max. 95 LOS Delay th % Max. 95 LOS Delay th % V/C Queue V/C Queue V/C Queue Mid Rivers Mall Drive & North Outer Road/Main Street Eastbound Main Street B (T) C (R) C (R) Westbound North Outer Road B (L) E (L) D (L) Northbound Mid Rivers Mall Dr. B (T) C (L) C (T) Southbound Mid Rivers Mall Dr. C (T) E (T) D (T) Overall Intersection B D D Mid Rivers Mall Drive & I-70 Westbound Off-Ramp Westbound WB Entrance Ramp B (L) C (L) D (L) Northbound Mid Rivers Mall Dr. A (T) A (T) A (T) Southbound Mid Rivers Mall Dr. A (T) B (T) A (L) Overall Intersection B C C Mid Rivers Mall Drive & I-70 Eastbound Exit Ramp/Veterans Memorial Parkway Eastbound I-70 EB Exit Ramp E (T) E (R) F (R) Northbound Mid Rivers Mall Dr. B (R) C (T) E (T) Southbound Mid Rivers Mall Dr. C (T) E (T) C (T) Overall Intersection D D E Mid Rivers Mall Drive & Mid Rivers Mall Eastbound Mid Rivers Mall D (T) D (T) D (T) Westbound Mid Rivers Mall B (T) D (T) D (T) Northbound Mid Rivers Mall Dr. A (T) B (T) C (T) Southbound Mid Rivers Mall Dr. B (T) D (T) D (T) Overall Intersection A D D Page 47

49 Continue Table 10: 2030 No Build Intersection Operating Conditions Mid Rivers Mall Drive Corridor (Synchro) Mid Rivers Mall Drive & Suemandy Road Eastbound Suemandy Road E (L) E (L) E (L) Westbound Suemandy Road D (L) E (L) E (L) Northbound Mid Rivers Mall Dr. A (T) B (L) B (T) Southbound Mid Rivers Mall Dr. A (L) C (T) D (T) Overall Intersection B D D Mid Rivers Mall Drive & Barnes Noble Entrance Eastbound Barnes Noble Entrance E (L) D (L) D (L) Westbound Barnes Noble Entrance D (R) D (T) D (L) Northbound Mid Rivers Mall Dr. A (T) A (T) B (T) Southbound Mid Rivers Mall Dr. A (T) B (T) B (T) Overall Intersection A B C Mid Rivers Mall Drive & McMenamy Road Eastbound McMenamy Road D (L) D (L) D (L) Westbound McMenamy Road D (T) D (L) C (L) Northbound Mid Rivers Mall Dr. B (T) B (T) B (T) Southbound Mid Rivers Mall Dr. A (T) B (T) A (T) Overall Intersection B B B North Outer Road & North Spencer Loop Eastbound North Outer Road A (T) A (T) A (T) Westbound North Outer Road B (T) B (T) B (T) Southbound N. Spencer Loop B (L) B (L) B (L) Overall Intersection A B B Veterans Memorial Parkway & Mid Rivers Mall Right-In/Right-Out Eastbound Right-In A A A Northbound Right-Out D C D Page 48

50 Table 11: 2030 No Build Intersection Operating Conditions Mid Rivers Mall Drive Corridor (VISSIM) AM Peak Hour (7:30 8:30) PM Peak Hour (4:45 5:45) SAT Peak Hour (11:45 12:45) VISSIM Ave. Max Ave. Max Ave. Max Intersection/Movement LOS Delay LOS Delay LOS Delay Queue Queue Queue Queue Queue Queue Mid Rivers Mall Drive & North Outer Road/Main Street Eastbound Main Street B F C Westbound North Outer Road C E D Northbound Mid Rivers Mall Dr. A B B Southbound Mid Rivers Mall Dr. C F C Overall Intersection B E C Mid Rivers Mall Drive & I-70 Westbound Off-Ramp Westbound WB Entrance Ramp C D D Northbound Mid Rivers Mall Dr. A C B Southbound Mid Rivers Mall Dr. A B B Overall Intersection B C C Mid Rivers Mall Drive & I-70 Eastbound Exit Ramp/Veterans Memorial Parkway Eastbound I-70 EB Exit Ramp D D F Northbound Mid Rivers Mall Dr. C C B Southbound Mid Rivers Mall Dr. B B B Overall Intersection C C C Mid Rivers Mall Drive & Mid Rivers Mall Eastbound Mid Rivers Mall D D D Westbound Mid Rivers Mall D F F Northbound Mid Rivers Mall Dr. B C C Southbound Mid Rivers Mall Dr. A B C Overall Intersection B C D Page 49

51 Continue Table 11: 2030 No Build Intersection Operating Conditions Mid Rivers Mall Drive Corridor (VISSIM) Mid Rivers Mall Drive & Suemandy Road Eastbound Suemandy Road D D D Westbound Suemandy Road C D D Northbound Mid Rivers Mall Dr. B B B Southbound Mid Rivers Mall Dr. B B B Overall Intersection B C C Mid Rivers Mall Drive & Barnes Noble Entrance Eastbound Barnes Noble Entrance D C D Westbound Barnes Noble Entrance C D D Northbound Mid Rivers Mall Dr. A A B Southbound Mid Rivers Mall Dr. A A A Overall Intersection A A B Mid Rivers Mall Drive & McMenamy Road Eastbound McMenamy Road C D C Westbound McMenamy Road D D D Northbound Mid Rivers Mall Dr. A B B Southbound Mid Rivers Mall Dr. A A A Overall Intersection A A A North Outer Road & North Spencer Loop Eastbound North Outer Road A A A Westbound North Outer Road A A A Southbound N. Spencer Loop A A A Overall Intersection A A A Veterans Memorial Parkway & Mid Rivers Mall Right-In/Right-Out Eastbound Right-In A A A Northbound Right-Out F F F Overall Intersection A A B Page 50

52 Synchro Intersection/Movement Mid Rivers Mall Drive/I-70 & Route 79/I-70 Interchanges Study Table 12: 2030 No Build Intersection Operating Conditions Route 79/Salt Lick Road Corridor (Synchro) AM Peak Hour (7:30 8:30) PM Peak Hour (4:45 5:45) SAT Peak Hour (11:45 12:45) Max. 95 LOS Delay th % Max. 95 LOS Delay th % Max. 95 LOS Delay th % V/C Queue V/C Queue V/C Queue Route 79 & I-70 Westbound Off-Ramp Westbound I-70 WB Exit Ramp C (L) D (L) Northbound Route 79 C (T) D (L) Southbound Route 79 C (T) F (T) Overall Intersection C E Route 79 & I-70 Eastbound Off-Ramp Eastbound Left-Turn F > F > Eastbound Right-Turn F > F > Salt Lick Road & Veterans Memorial Parkway Eastbound Veterans D (L) F (L) Westbound Veterans C (T) C (T) Northbound Salt Lick C (T) C (T) Southbound Salt Lick B (T) E (T) Overall Intersection C E Salt Lick Road & Dierberg s Right-In/Right-Out Eastbound Right-Turn A C Southbound Right-Turn A A Salt Lick Road & Janis Ann Drive Eastbound Janis Ann D (L) C (L) Westbound Janis Ann C (T) C (L) Northbound Salt Lick B (T) C (T) Southbound Salt Lick B (T) C (T) Overall Intersection B C Page 51

53 VISSIM Intersection/Movement Mid Rivers Mall Drive/I-70 & Route 79/I-70 Interchanges Study Table 13: 2030 No Build Intersection Operating Conditions Route 79/Salt Lick Road Corridor (VISSIM) AM Peak Hour (7:30 8:30) PM Peak Hour (4:45 5:45) SAT Peak Hour (11:45 12:45) Ave. Max Ave. Max Ave. Max LOS Delay LOS Delay LOS Delay Queue Queue Queue Queue Queue Queue Route 79 & I-70 Westbound Off-Ramp Westbound I-70 WB Off-Ramp B B Northbound Route 79 B F Southbound Route 79 A D Overall Intersection B D Route 79 & I-70 Eastbound Off-Ramp Eastbound Left-Turn F F Eastbound Right-Turn E F Salt Lick Road & Veterans Memorial Parkway Eastbound Veterans Memorial Pkwy. D E Westbound Veterans Memorial Pkwy. C C Northbound Salt Lick Road A B Southbound Salt Lick Road A A Overall Intersection B B Salt Lick Road & Dierberg s Right-In/Right-Out Eastbound Right-Turn A A Southbound Right-Turn B B Salt Lick Road & Janis Ann Drive Eastbound Janis Ann Drive D C Westbound Janis Ann Drive C C Northbound Salt Lick Road A A Southbound Salt Lick Road A B Overall Intersection B B Page 52

54 HCS+ SECTION Table 14: 2030 No Build Conditions Freeway Analysis Results (HCS+) PM Peak Hour AM Peak Hour DIRECTION TYPE LOS Density (pc/mi/ln)* Avg. Speed (mph)** LOS Mid Rivers Mall Drive/I-70 & Route 79/I-70 Interchanges Study Density (pc/mi/ln)* Avg. Speed (mph)** LOS Saturday Mid Day Peak Hour Density (pc/mi/ln)* West of Route 79 EB Freeway D C Between Route 79 & Mid Rivers Mall Interchanges Avg. Speed (mph)** EB Freeway D C C Mid Rivers Mall Loop On-Ramp EB Merge D C C East of Mid Rivers Mall Loop Ramp EB Freeway D C C Between Mid Rivers Mall & Route 370 Interchanges EB Freeway D C C Between Route 370 & Mid Rivers Mall Interchanges WB Freeway B D B Mid Rivers Mall Loop On-Ramp WB Merge B D C Mid Rivers Mall On-Ramp WB Merge B F B Between Mid Rivers Mall & Route 79 Interchanges WB Freeway C F C Route 79 Off-Ramp WB Diverge A F Route 79 On-Ramp WB Merge B F West of Route 79 Interchange WB Freeway B E * pc/mi/ln = passenger cars per mile per lane ** mph = miles per hour Page 53

55 VISSIM SECTION Table 15: 2030 No Build Conditions Freeway Analysis Results (VISSIM) PM Peak Hour AM Peak Hour DIRECTION TYPE LOS Density (pc/mi/ln)* Avg. Speed (mph)** LOS Mid Rivers Mall Drive/I-70 & Route 79/I-70 Interchanges Study Density (pc/mi/ln)* Avg. Speed (mph)** LOS Saturday Mid Day Peak Hour Density (pc/mi/ln)* West of Route 79 EB Freeway C C Route 79 Off-Ramp EB Diverge C C Route 79 Loop On-Ramp EB Merge D C Route 79 On-Ramp EB Merge D B Between Route 79 & Mid Rivers Mall Interchanges Avg. Speed (mph)** EB Freeway D C F Mid Rivers Mall Off-Ramp EB Diverge D B F Mid Rivers Mall Loop On-Ramp EB Merge C B B East of Mid Rivers Mall Loop Ramp EB Freeway D C B Veteran Memorial Parkway Slip On- Ramp EB Merge C B B Between Mid Rivers Mall & Route 370 Interchanges EB Freeway D C B Between Route 370 & Mid Rivers Mall Interchanges WB Freeway B F B Mid Rivers Mall Off-Ramp WB Diverge B F B Mid Rivers Mall Loop On-Ramp WB Merge B F B Mid Rivers Mall On-Ramp WB Merge B F B Between Mid Rivers Mall & Route 79 Interchanges WB Freeway B F C Route 79 Off-Ramp WB Diverge B D Route 79 On-Ramp WB Merge B C West of Route 79 Interchange WB Freeway B C * pc/mi/ln = passenger cars per mile per lane ** mph = miles per hour Page 54

56 Alternative Development A wide range of alternatives were considered for mainline I-70 as well as for the Mid Rivers Mall Drive and Route 79 interchanges. I-70 Alternatives Two mainline I-70 alternatives were developed to address 3 major existing problems: 1) underutilized pavement on westbound I-70, 2) inadequate capacity on westbound I-70, and 3) weaving on I-70 between Mid Rivers Mall Drive and Route 79. While one third of the lanes exit at Mid Rivers Mall Drive, by 2030 only 15% of vehicles are expected to exit at Mid Rivers Mall Drive. As a result, the right two lanes are underutilized on westbound I-70. Secondly by 2030, traffic demand will be 8,865 vehicles per hour (vph) during the PM peak period for westbound I-70, but available capacity will only be 7,435 vph. As a result, the expected average speeds on I-70 will only be 15 mph east of Mid Rivers Mall Drive and 34 mph west of Mid Rivers Mall Drive. Lastly, by 2030, 1,500 vph are expected to enter westbound I-70 from Mid Rivers Mall Drive during the PM peak period and 2,300 vph are expected to exit westbound I-70 at Route 79. No auxiliary lane is currently provided on westbound I-70 for this weaving movement. A first alternative is to add a westbound I-70 auxiliary lane between Mid Rivers Mall Drive and Route 79. This helps in addressing the lane balance problem by providing a fifth westbound lane through the interchange. As a result, 16% of the lanes would exit at Mid Rivers Mall Drive, matching the 15% of vehicles exiting at that location. This alternative provides an auxiliary lane on westbound I-70 between Mid Rivers Mall Drive & Route 79 and provides the capacity required to serve the 2030 traffic demand. As a result, the average speeds on I-70 are improved to 61 mph east of Mid Rivers Mall Drive. For a second alternative, adding a westbound one-way road between Mid Rivers Mall Drive and Route 79 addresses the lane balance problem by shifting more exiting traffic to the Mid Rivers Mall Drive/Route 79 exit. Consolidating these exits results in 41% of the traffic stream exiting the freeway at this location (as compared to one third of the lanes exiting). Weaving is eliminated from the freeway and the need for an auxiliary lane on westbound I-70 between Mid Rivers Mall Drive & Route 79 is eliminated. This alternative provides the capacity required to serve the 2030 traffic demand. As a result, the average speeds on I-70 are improved to 62 mph east of Mid Rivers Mall Drive and to 55 mph west of Mid Rivers Mall Drive. One sub-option that was considered during the study was to provide for a three lane westbound off-ramp at Mid Rivers Mall Drive/Route 79. In this scenario the two right-most I-70 lanes would be dedicated exiting lanes, the three left-most lanes would be dedicated through lanes on I-70, and the third lane from the right would be a shared exit/through lane. This configuration would result in a better distribution of traffic between the lanes on I-70. This option was not included in the final westbound one-way outer road between Mid Rivers Mall Drive and Route 79 concept because it would drop two through lanes at the Mid Rivers Mall Drive/Route 79 exit. However, it should be reconsidered during the Access Justification Report (AJR)/design phase of the project, if this alternative were to move forward. Mid Rivers Mall Drive Interchange Alternatives Mid Rivers Mall Drive interchange alternatives were developed primarily to solve congestion and safety issues at the interchange. Specifically, four issues are present at this interchange. The first issue is Page 55

57 northbound Mid Rivers Mall Drive has poor utilization of traffic using the left lanes. All movements onto I- 70 are right-turn movements, which forces traffic to crowd the right lane. This problem is exacerbated by the fact that the Mid Rivers Mall is located on the east side of the road, also drawing traffic into the right lane. Traffic currently queues in the right lane to Suemandy Drive. By 2030 these queues are expected to reach Mexico Road on a regular basis. The second issue is Saturday traffic is heavy along Mid Rivers Mall Drive due to the concentration of commercial uses just south of I-70. During peak shopping periods, delays at the signalized intersections can become heavy and vehicles exiting eastbound I-70 at Mid Rivers Mall Drive frequently queue onto the interstate. This traffic is likely to impact I-70 operations on a regular basis by The third issue is the mixing of commuter and retail oriented traffic results in heavy traffic movements onto and off of the interstate. The movements between the east and south are especially pronounced. The heavy westbound off-ramp traffic currently queues far onto the ramp, and is expected to reach I-70 on a regular basis by The fourth issue is the North Outer Road is positioned too close to the westbound I-70 ramp intersections. This spacing results in poor signal progression and creates difficult maneuvers for trucks, which frequent the truck-stop in the northwest quadrant of the interchange. Although several concepts were considered, the initial screening process determined that two primary alternatives were viable. These alternatives were the Diverging Diamond Interchange with eastbound I-70 to Veterans Memorial Parkway Bonus Ramp and the Tight Diamond Interchange with Texas U Turn. Diverging Diamond with Eastbound I-70 to Veterans Memorial Parkway Bonus Ramp The primary benefit of the Diverging Diamond Interchange (DDI) with eastbound I-70 to Veterans Memorial Parkway Bonus Ramp is the superior levels of service/operating conditions. In fact, this alternative evaluated better than any other interchange concept considered. Figure 25 shows the Diverging Diamond Interchange. One of the ways that the DDI improves operations is that it allows northbound Mid Rivers Mall Drive to westbound I-70 traffic to travel in the left-lanes of Mid Rivers Mall Drive, vastly improving lane utilization and enhancing overall traffic operations. The DDI would retain the existing bridge structure, keeping costs low and allowing for a compact interchange footprint. The eastbound I-70 to Veterans Memorial Parkway bonus ramp was considered necessary to maintain quality access to Mid Rivers Mall. Another benefit of this ramp is that it could relieve southbound Mid Rivers Mall Drive by enhancing access to the Grand Teton corridor. This alternative is compatible with a one way outer road concept as well as potential improvements to the intersection of the North Outer Road and Mid Rivers Mall Drive. This concept involves considerable modifications to the existing freeway ramps and commuter lot. Moreover, the design of the bonus ramp tie-in to Veterans Memorial Parkway needs to be considered during the project s design phase. This ramp may complicate traffic flows along eastbound Veterans Page 56

58 HORNER & SHIFRIN, INC. ENGINEERS I-70/MID RIVERS MALL DRIVE ALTERNATIVE 1: DIVERGING DIAMOND FIGURE 25

59 Memorial Parkway adjacent to the mall, and modified access between the mall and Veterans Memorial Parkway should be considered. Tight Diamond with Texas U Turn The Tight Diamond with Texas U Turn would also provide for improved levels of service/operating conditions. Figure 26 displays this interchange option. This interchange concept would also allow northbound Mid Rivers Mall Drive to westbound I-70 traffic to travel in the left-lanes of Mid Rivers Mall Drive, improving lane utilization and enhancing overall traffic operations. Moreover, tight diamond interchanges are common in the St. Louis area, making navigation intuitive. However, traffic would saturate this interchange concept by Tight Diamond Interchanges do not facilitate traffic progression as well as DDI interchange at locations with heavy entering and existing traffic volumes. As a result, traffic signal operations at tight-diamond interchanges are constrained as compared to DDI interchanges. The Tight Diamond with Texas U Turn would retain the existing bridge structure (with some bridge widening to accommodate the U-Turn), keeping costs low and allowing for a compact interchange footprint. This alternative is compatible with a one way outer road concept as well as potential improvements to the intersection of the North Outer Road and Mid Rivers Mall Drive. This alternative allows for easy access to Veterans Memorial Parkway from both eastbound and westbound I-70. Because of this access, the Tight Diamond with Texas U-Turn Interchange concept could relieve southbound Mid Rivers Mall Drive by enhancing access to the Grand Teton corridor. This concept involves considerable modifications to the existing freeway ramps and commuter lot. Moreover, the design of the Texas U-Turn tie-in to Veterans Memorial Parkway needs to be considered during the project s design phase. This ramp may complicate traffic flows along eastbound Veterans adjacent to the mall, and modified access between the mall and Veterans Memorial Parkway should be evaluated. Alternatives Considered but Eliminated due to Traffic Operations Concerns Several alternatives were considered but dropped because they were unlikely to provide for acceptable traffic operations. Single Point Urban Interchange A Single Point Urban Interchange (SPUI) as shown in Figure 27 would allow northbound Mid Rivers Mall Drive to westbound I-70 traffic to travel in the left-lanes of Mid Rivers Mall Drive, improving lane utilization and enhancing overall traffic operations. This is a compact interchange design, allowing improvements to be made within MoDOT s right of way. Moreover, SPUI are common in the St. Louis area, making navigation intuitive. However, the traffic movements at the Mid Rivers Mall Drive interchange do not lend themselves well to a SPUI. The major traffic movements would still require separate signal phases, eliminating the benefits of Page 58

60 HORNER & SHIFRIN, INC. ENGINEERS I-70/MID RIVERS MALL DRIVE ALTERNATIVE 4J: TIGHT DIAMOND WITH TEXAS U-TURN FIGURE 26

61 X HORNER & SHIFRIN, INC. ENGINEERS I-70/MID RIVERS MALL DRIVE ALTERNATIVE 5: SINGLE-POINT URBAN INTERCHANGE FIGURE 27

62 the SPUI design. This concept would operate at LOS F and was eliminated due to unacceptable traffic operations. Additionally, the high-cost of modifying the existing structure would constrain the feasibility of this concept. Folded Diamond A folded diamond interchange would retain the existing bridge structure and most of the existing freeway ramps (and thus not impacting mall access via Veterans Memorial Parkway). Figure 28 displays the folded diamond interchange alternative. However, the concept would provide for marginal levels of service/operating conditions. It would not address existing northbound lane utilization constraint or any other operational constraints on the south side of the interchange. It would also necessitate the North Outer Road to be reconfigured (i.e., one way) or relocated. This concept would operate at LOS F and was eliminated due to unacceptable traffic operations. Continuous Flow Intersection with Relocated Loop Ramp Likewise, an interchange concept including a Continuous Flow Intersection with Relocated Loop Ramp, as illustrated in Figure 29, would provide for marginal levels of service/operating conditions. This concept would not address operational constraints on the south side of the interchange. This concept would operate at LOS F and was eliminated due to unacceptable traffic operations. It would include some traffic movements that would be awkward for unfamiliar motorists and diminishes mall access via Veterans Memorial Parkway for those vehicles exiting westbound I 70. Relocated Loop Ramp Alternatives were considered that would relocate the loop ramp from the northeast quadrant of the interchange to the northwest quadrant of the interchange. The concept would be to allow a traditional left turn for the northbound to westbound traffic movement and allow a free-flow westbound to southbound traffic movement. Figure 30 shows the relocated loop ramp option. However, this concept introduced an unacceptable southbound weaving movement on Mid Rivers Mall Drive over I-70, and was eliminated. Roundabouts Various alternatives were considered which would incorporate roundabouts at the Mid Rivers Mall Drive interchange ramp terminals. The roundabouts alternative is depicted in Figure 31. While these concepts could have some benefits, the traffic volumes along Mid Rivers Mall Drive are too heavy for roundabouts to operate efficiently. Mid Rivers Mall Drive North Outer Road Alternatives Several configurations were considered for the intersection of the North Outer Road and Mid Rivers Mall Drive. Some configurations, such as concepts to offset north outer roads and displace the northbound leftturn onto westbound I-70 are not compatible with the DDI concept, and were therefore eliminated from Page 61

63 HORNER & SHIFRIN, INC. ENGINEERS I-70/MID RIVERS MALL DRIVE ALTERNATIVE 2: FOLDED DIAMOND RESTRIPE NB LANES FIGURE 28

64 HORNER & SHIFRIN, INC. ENGINEERS I-70/MID RIVERS MALL DRIVE ALTERNATIVE 3E: CONTINUOUS FLOW WITH RELOCATED LOOP RAMP FIGURE 29

65 HORNER & SHIFRIN, INC. ENGINEERS I-70/MID RIVERS MALL DRIVE ALTERNATIVE 3I: RELOCATED LOOP RAMP FIGURE 30