PRELIMINARY DRAFT WADDLE ROAD / I-99 INTERCHANGE PROJECT ALTERNATIVE ANALYSIS FINAL TRAFFIC SUMMARY REPORT Prepared by: In Association with: November 2013
EXECUTIVE SUMMARY Patton Township, in partnership with the Pennsylvania Department of Transportation (PennDOT), initiated the Waddle Road / I-99 Interchange project to increase capacity and improve safety at the interchange and on the adjacent road network. The project study area, including the Waddle Road / I-99 Interchange (Exit 71 Woodycrest, Toftrees), is located in Patton Township, Centre County, Pennsylvania, just on the fringe of State College and Penn State University. Travel along the Waddle Road Corridor and the Interchange is currently subject to heavy traffic congestion and queuing, especially on the I-99 SB / U.S. 322 WB offramp. Significant growth is planned just north of the interchange within the Toftrees Community, and the added traffic from the development onto the immediate and surrounding area will require improvements to the Interchange. These improvements are considered to be critical to the local economic development initiatives and necessary to support the existing and future land development needs over the long term for the area. Existing Conditions The primary study area is shown in Figure 2 and can best be described as a mixture of retail, commercial, office and residential land uses. Overall, the Waddle Road corridor has a land use context which corresponds to the Suburban Corridor/Center definition in the PennDOT Smart Transportation Guidebook. Several major roadways were studied as part of this project, mostly consisting of Township roads. Additionally, five signalized intersections, which are interconnected with the on-street master controller located at Colonnade Boulevard, were also evaluated as part of this project. Waddle Road / I-99 SB Rt. 322 WB Waddle Road / I-99 NB Rt. 322 EB Waddle Road / Colonnade Boulevard Waddle Road / Strouse Avenue Waddle Road / Clearview Avenue It should also be noted that with Penn State University s Beaver Stadium in close proximity, the I-99 / Waddle Road interchange is part of a special event route for departing traffic leaving home football games. The route utilizes Fox Hollow Road, Toftrees Avenue and Waddle Road. Pedestrian traffic within the study area is accommodated by a limited sidewalk network confined largely to Colonnade Boulevard and segments along Waddle Road that are discontinuous south of Colonnade Boulevard. To the north, pedestrians must use the existing 4 to 5 foot shoulders on the bridge structure to cross I-99. Bicycle lanes are provided on Colonnade Boulevard. Waddle Road north of Colonnade Boulevard to Toftrees Avenue is considered a preferred local bicycle route as identified in the Patton Township Bicycle and Pedestrian Patch Study. Also, Waddle Road route north to Toftrees is shown as a proposed facility on the Centre Region Bike Map. Within the study area, local transit service is provided by the Centre Area Transportation Authority (CATA). CATA currently has three fixed routes that serve the area. Upon review of the available traffic data within the study area and with the identification of the traffic data required to evaluate the improvement alternatives, a comprehensive data collection effort was undertaken. The data collection effort included automatic traffic recorder (ATR) counts, manual turning movement counts (TMC), and field observations. ATR counts were conducted at nine (9) locations over a seven-day period in April 2012. The results of the counts show that the daily traffic volumes are highest on Fridays, with only a slight variation in volumes between the weekday and Saturday traffic volumes. The manual i
counts were conducted at the five signalized study intersections during a typical weekday and a Saturday in April 2012 during the AM peak period (7:00 9:00 AM), Mid-day peak periods (9:30 10:30 AM / 1:30 2:30 PM), PM peak period (3:30 6:30 PM) and Saturday peak period (3:00 6:00 PM). Without the exception, the highest traffic volumes were observed during the PM peak hour. Field observations were made at the study intersections throughout a typical week in April 2012. Observations of the traffic flow patterns at the study intersections help determine how, when, and why reoccurring traffic congestion occurs. Some of the significant observations related to the traffic flow occurring within the study area include: Of the five study intersections, the Waddle Road / I-99 SB Route 322 WB on-off ramp intersection experiences the greatest congestion. Specifically on Friday, the queues on the ramp get so long that the traffic gets close to impeding on the mainline I-99 traffic. Based on ATR count data, Friday peak hour traffic volumes are over 20 percent higher than the typical weekday. Generally, all vehicles queued on the westbound off-ramp at the Waddle Road / I-99 SB Route 322 WB on-off ramp make it through the signal on green except during the Friday peak hour and during isolated times during the weekday PM peak hour and the Saturday peak hour. A maximum of 25-27 vehicles on the ramp are able to make it through the green phase. An existing capacity analysis of the signalized intersections was conducted utilizing the methodology outlined in the Transportation Research Board s Highway Capacity Manual 2000 (HCM) and incorporated in the Synchro analysis software. Overall, all the intersections are operating at an LOS D or better, although some individual movements are currently operating at an LOS E as noted below: Waddle Road / I-99 NB Rt. 322 EB Ramp (PM Peak Hour) Waddle Road / Colonnade Boulevard (PM Peak Hour) Waddle Road / Strouse Avenue (PM Peak Hour) Waddle Road / Clearview Avenue (PM Peak Hour) Synchro was also used to analyze vehicle queuing and the longest queues were found on the following approaches: Waddle Road / I-99 Rt. 322 WB Ramp westbound approach (PM Peak Hour) Waddle Road / I-99 Rt. 322 EB Ramp southbound approach (PM and Saturday Peak Hour) For analysis of crash experience and safety issues within the project area, reportable accident data over a five-year period (January 1, 2006 through December 31, 2010) was obtained from PennDOT s Bureau of Highway Safety and Traffic Engineering. Additionally, reportable and non-reportable crash data was obtained from Patton Township for the five-year period. None of the study intersections analyzed have experienced a high number of crashes. Additionally, a review of the reportable crash data shows no more than four crashes occurred at an intersection in any given year and no crashes resulted in fatalities. An average crash rate segment analysis of the Waddle Road corridor was also performed to determine a composite rate for comparison. The analysis was performed by comparing the rate of crashes reported along Waddle Road to the average PennDOT rate of crashes for a roadway with similar attributes (physical characteristics and traffic conditions). Waddle Road experienced an accident rate similar to the statewide ii
average. Additionally, a 1.0 mile segment of Interstate 99 was also analyzed. Only nine crashes occurred on this section of I-99 over the five-year period resulting in a segment accident rate almost four times less than the PennDOT accident rate for similar roadways. Short Term/Early Action Improvements During the scoping of this project, Patton Township expressed interest in the consultant design team developing short term early action improvements which would be cost effective and relatively easy to implement, and would provide an immediate, positive impact to the daily reoccurring congestion along the corridor. Upon completion of the comprehensive evaluation of existing conditions and after numerous field views and discussions with Township and PennDOT officials, it was agreed that some preliminary projects should be studied and possibly initiated prior to the long term improvements which could evolve from this project. These improvements to be evaluated were categorized as Early Action Improvements. The analysis independently evaluated these improvements to determine if any low-cost solutions could be implemented to provide an immediate positive impact. The following improvements are provided for consideration: 1. For an immediate action, implement low-cost signal timing optimization improvements consisting of the following: Reducing cycle lengths Adjusting off-sets Reallocating green time between phases Adding a Friday Event to the coordination program Eliminating the I-99/Route 322 ramp flash mode during Black Friday weekend The traffic signal permits have been revised and approved by PennDOT. 2. Conduct ATR traffic counts during the Black Friday Event weekend to use in the future development of a Black Friday Coordination Event. 3. Install ramp pre-emption on the I-99 SB / Route 322 WB off Ramp when Township funding is available. Construction costs will range from $10,000.00 to $12,000.00 with a pre-emption loop placed at 1,000 feet from the stop bar. Once completed, Patton Township should monitor the performance of the recommended early action improvements to ensure the desired effects are taking place. It is very likely that some additional fine tuning of the signal timings will be necessary. Improvement Alternatives Preliminary 2040 Traffic Analysis One of the first steps taken in determining the future no-build traffic conditions was to compare the Centre Region Planning Agency (CRPA) approved 2040 Centre Region Growth Forecasts with the approved development activity for Patton Township. The comparison found that the CRPA 2040 Forecast included more than 1.7 times the non-residential growth and 3.1 times the residential growth than the approved development activity. In reality, development activity has been slowed by the economy with the Township approving 40 residential building permits on an average over recent years. In addition, large master plan communities like Toftrees East have taken years to develop to their present state. Following the review iii
and approval of the CRPA 2040 Growth Forecast for Patton Township by PennDOT District 2-0, it was concluded the use of the Centre County Travel Demand Model (CCTDM) for determining the future 2040 traffic conditions was appropriate at this point in the project development process. For the preliminary 2040 no-build traffic conditions, those intersections which show an overall LOS E or F and are unacceptable are: Waddle Road/ I-99 SB Rt. 322 WB ramp (PM Peak Hour) Waddle Road / I-99 NB Rt. 322 EB ramp (PM Peak Hour) Waddle Road/Colonnade Blvd. (PM Peak Hour) The overall LOS at the Waddle Road intersections with Strouse Avenue and Clearview Avenue improves, operating at an LOS A with the optimization of signal timings and the corridor cycle length. An overall LOS D and above is considered acceptable. Vehicle queues were also evaluated for the 2040 No-build conditions using Synchro and the optimized signal timings. With the deterioration in the level of service and increased delays, vehicle queues increased significantly for the following approaches: Waddle Road/ I-99 SB Rt. 322 WB ramp and southbound approach (PM and Saturday Peak Hour) Waddle Road/Colonnade Blvd southbound approach (PM and Saturday Peak Hour) For the purpose of the traffic analysis, five (5) build alternatives for the interchange were selected for the preliminary evaluation. The evaluation focused on traffic performance of the alternatives with particular emphasis on intersection levels of service and capacity, and vehicle queue results. Specifically, the following interchange build alternatives were considered: Conventional Diamond Interchange Partial Cloverleaf Interchange Diverging Diamond Interchange (DDI) Multilane Roundabouts Single Point Urban Interchange (SPUI) For the traffic evaluation and comparison of the build alternatives, the no-build 2040 design year preliminary traffic volumes were used in the traffic alternatives evaluation. Due to the preliminary nature of the CCTDM, CRPA did not make special travel model runs for the build alternatives for the preliminary evaluation. While time and funding constraints were a factor, it was felt that the changes to the interchange are spot improvements in terms of the overall roadway network and alternate build runs would not produce significantly different results from the no-build 2040 design year volumes. The five build alternatives were evaluated based on their traffic performance in improving the existing diamond interchange to accommodate the 2040 design year preliminary traffic volumes. All build alternatives provided a desirable LOS C at the interchange, with the exception of the two lane multilane roundabout. The diverging diamond interchange alternative (DDI) showed issues with queuing between the ramp termini, which is inherent with DDIs when spacing becomes 500 to 600 feet and there is one controller for the interchange. With the remaining build alternatives providing similar acceptable levels of service for the 2040 design year, the conventional diamond alternative, which is an expansion to the current diamond interchange configuration, and viewed as the most pedestrian and bicycle friendly, may be considered as one of the preferred alternatives. The preferred alternatives would be advanced for refinement to address the following technical comments associated with the 2040 design year preliminary traffic analysis results: iv
Updated CCTM and study area model calibration Final 2040 Design Year Traffic Volumes Waddle Road southbound queuing and spillback issues at Colonnade Boulevard For the updated traffic analysis, it was decided that both the Conventional Diamond (CD) and Partial Cloverleaf (PC) build alternatives would be further evaluated in the updated traffic analysis of the preferred build alternatives. Preferred Alternatives Updated 2040 Traffic Analysis Based on the earlier preliminary traffic analysis evaluation of several build alternatives, the Conventional Diamond (CD) and Potential Cloverleaf (PC) build alternatives were selected as the preferred alternatives to be further evaluated with the updated traffic analysis. Specifically, the updated traffic analysis included the following: New intersection manual counts and unmet traffic demand observations HCM 2010 / Synchro 8-0 / SimTraffic Analysis Multi-period Analysis Final Centre County travel demand model Evaluation of improvement options to Colonnade Blvd intersection The analysis follows the directions provided in PennDOT Strike-off Letter (SOL) 494-13-03 regarding the 2010 Highway Capacity Manual (HCM) and traffic data collection analysis, and simulation specific to Pennsylvania. Since the preliminary travel model output was provided in September 2012, the CCTDM has been finalized and determined to be suitable for the updated traffic analysis. A subarea focusing approach was taken which has the advantage of retaining the County highway network system and trip table, thus allowing the interaction of the study area with the region. An important step in the travel model calibration process for the study area was to check the accuracy and reasonableness of 2010 base year daily traffic assignments to actual volumes. This involved an iterative process of running the base year travel model and making adjustments until the desired accuracy and reasonableness was achieved. A final check of the 2010 base year daily traffic volume assignment showed an overall accuracy of 3 percent for the project study area. Also, actual link volumes were well within the maximum desirable deviation allowed. The final 2040 no-build traffic volumes were derived from the traffic NCHRP 255 forecasting methodology and adjustment process. With the land use forecast, traffic is expected to grow significantly in the study area. Waddle Road through the interchange will see an average growth of 87 percent. Those intersections which show an overall LOS E or F and are unacceptable are: Waddle Road / I-99 SB Rt. 322 WB ramp (PM Peak Hour) Those intersections which show an approach or movement at an LOS E or F are: Waddle Road / I-99 SB Rt. 322 WB ramp (AM and Sat Peak Hour) Waddle Road / I-99 NB Rt. 322 EB ramp (AM, PM and Sat Peak Hour) Waddle Road / Colonnade Blvd. (PM Peak Hour) Waddle Road / Strouse Avenue (PM and Sat Peak Hour) Waddle Road / Clearview Avenue (PM and Sat Peak Hour) The overall LOS at the Waddle Road intersections with Strouse Avenue and Clearview Avenue improves, operating at an LOS A with the optimization of signal timings and the corridor cycle length. An overall LOS v
D is considered acceptable. Vehicle queues were also evaluated for the final 2040 no-build conditions using SimTraffic and the optimized signal timings. With the deterioration in the level of service and increased delays, vehicle queues increased significantly for the following approaches: Waddle Road / I-99 SB Rt. 322 WB ramp approach (AM, PM and Sat Peak Hour) Waddle Road / I-99 NB Rt. 322 EB ramp approach (PM Peak Hour) Waddle Road / Colonnade Blvd eastbound approach (PM Peak Hour) Waddle Road northbound approach through Clearview, Strouse and Colonnade Blvd (PM Peak Hour) For the final 2040 build traffic conditions, the following preferred alternatives were evaluated with the updated traffic analysis: 1. Conventional Diamond - This build alternative would widen the existing conventional diamond interchange to provide a six lane bridge and include the following lane configuration: Two northbound and southbound through lanes Side by side northbound and southbound left turn lanes Dual left turn lanes and right turn lanes on the westbound ramp High type channelized northbound right turn lane at the eastbound ramp Separate right and left turn lanes on the eastbound ramp Channelized southbound right turn lane at the westbound ramp The ramp termini would remain signalized. 2. Partial Cloverleaf - This build alternative would widen the existing bridge to six lanes and utilize a partial cloverleaf (Par Clo-B) in the northeast quadrant to accommodate the heavy westbound off-ramp left turn movements. Two northbound and southbound through lanes Dual left turn lanes on the eastbound ramp Existing westbound ramp becomes right turn only stop controlled Partial cloverleaf loop ramp is a free flowing movement onto Waddle Road Waddle Road northbound left turn movements onto I-99 SB would be controlled by a traffic signal High type channelized northbound right turn lane at the eastbound ramp While the build alternatives will add significant traffic capacity to the intersection, daily traffic volumes showed a 3 percent increase through the interchange area when compared to the no-build traffic volumes. The level of service and capacity analysis results were very similar for both preferred alternatives and there were no intersections that had an overall LOS less than D. An overall LOS D is considered acceptable. As expected, the Waddle Road / I-99 SB Rt. 322 WB ramp operated significantly better with the Partial Cloverleaf build alternative. Those signalized intersections which showed an approach or movement at an LOS E or F are: Waddle Road / I-99 NB / Rt. 322 EB ramp (PM and Sat Peak Hour) Waddle Road / Colonnade Blvd (PM Peak Hour) Waddle Road / Strouse Avenue (PM and Sat Peak Hour) Waddle Road / Clearview Avenue (PM and Sat Peak Hour) vi
Again, for both preferred alternatives the southbound through movement remained a problem during the PM peak hour period with a v/c ratio exceeding 1.0, a level of service F is shown despite a delay of 28 seconds. Vehicle queues were also evaluated for the 2040 build traffic conditions for each preferred alternative using SimTraffic and the optimized signal timings. For both preferred alternatives, southbound queuing is a problem during the PM peak hour period with the approach exceeding capacity (vc > 1.0). This causes spillback through the interchange and affects the queuing on the I-99 / Rt. 322 WB off ramp. For the northbound direction, the SimTraffic results show queuing and spillback between the Colonnade Blvd and Strouse Avenue intersections. To address the Waddle Road southbound through movement capacity and queuing / spillback issue, a range of improvement options were assessed at the Colonnade Blvd signalized intersection. The option to add an auxiliary second southbound through lane and retaining the split phasing was found to be the most effective in addressing the issue. The results are similar for both and all intersections should operate with an overall LOS C or better. The Strouse and Clearview Avenue approaches show a LOS E during the PM peak hour period but this can be contributed to the longer cycle length associated with the Conventional Diamond build alternative. The intersections should operate at a LOS A or B with both preferred alternatives. Vehicle queues were also evaluated for both preferred alternatives with the auxiliary through lane option. The results show that the Conventional Diamond build alternative is more effective in reducing southbound through lane queuing and spillback through the interchange. The PM peak hour (4:15 to 5:15 PM) 95 th percentile queue (618 ft) for this movement slightly exceeds the available stacking distance (605 ft) between Colonnade Blvd and the I-99 NB / Rt. 322 EB ramp. For this same time period, the Partial Cloverleaf build alternative shows significantly longer queues (752 ft) which causes additional spillback through the interchange. Overall, the southbound queues on Waddle Road at Colonnade Boulevard are over 20 percent longer with the Partial Cloverleaf build alternative and the auxiliary through lane option. The longer southbound queues are in part due to the elimination of traffic signal control at the I-99 / Rt. 322 WB off ramp which helped to control the vehicle arrivals southbound at Colonnade. The following are the major findings and conclusions of the preferred alternatives updated traffic analysis: 1. Major capacity improvements are required at the existing conventional diamond interchange (No-Build Alternative) to accommodate the 2040 design year traffic congestion and safety conditions. The major contributor to the need is the forecasted growth for the Toftrees West area. 2. Both the Conventional Diamond and Partial Cloverleaf preferred build alternatives should provide desired overall LOS C or better with the 2040 design year traffic volumes. However, southbound through lane capacity and queuing may remain a congestion and safety problem without improvements to the Colonnade Boulevard intersection. Spillback may occur through the interchange, largely during the PM peak hour period. 3. To address the southbound queuing / spillback issue, a range of improvement options were investigated at the Waddle Road / Colonnade Blvd intersection. An auxiliary southbound through lane through Colonnade Blvd was found to address the capacity issue for both the vii
preferred build alternatives. However, queuing and spillback through the interchange may remain a congestion and safety problem with the Partial Cloverleaf build alternative during a short portion of the PM peak hour period. Queue lengths on the southbound leg are approximately 20 percent longer with this alternative. 4. The Conventional Diamond build alternative is considered to be more pedestrian and bicycle friendly than the Partial Cloverleaf alternative. 5. The Conventional Diamond build alternative can be expanded to accommodate a Partial Cloverleaf (Par Clo - B) in the northwest quadrant in the future if traffic conditions and needs change. 6. In the design year 2040, Waddle Road south of Colonnade Blvd may become congested due to the through traffic volumes for a short portion of the PM peak hour period. Table 15 provides a summary performance comparison of the no-build and preferred alternatives. In conclusion, the Conventional Diamond build alternative, with the auxiliary through lane at Colonnade Blvd, was found to be the most cost effective improvement to accommodate the 2040 forecasted design year conditions. A conceptual design of the preferred build alternative is shown in Figure 24. viii
Intersection Measure of Effectiveness 2040 No Build TABLE 15 FINAL TRAFFIC PERFORMANCE COMPARISON NO BUILD AND BUILD ALTERNATIVES 2040 Build (Conventional Diamond) 2040 Build (Partial Cloverleaf) 2040 Build 2040 Build (Conventional Diamond (Partial Cloverleaf with with 2 Thru Lanes @ 2 Thru Lanes @ Colonnade) Colonnade) Overall LOS/Delay F (124.8) D (35.0) A (2.6) C (33.3) A (3.0) WB approach LOS F (134.2) D (53.8) D (28.9) D (44.6) D (28.9) NB approach LOS F (115.7) C (26.6) A (2.5) C (26.1) A (2.9) Waddle Road / I 99 SB 322 WB Ramps SB approach LOS F (113.2) C (28.4) A (2.7) C (30.8) A (3.1) WB queues 1705 1612 466 591 270 NBL queues 276 389 135 400 131 NBT queues 690 390 338 Any V/C ratio > 1.0? YES WBL, NBL, NBT, SBT NO NO NO NO Overall LOS/Delay D (46.0) C (25.4) C (20.0) C (22.3) B (15.1) EB approach LOS F (134.9) E (62.8) E (55.5) D (50.1) D (45.2) NB approach LOS A (0.4) A (0.1) C (23.4) A (0.1) A (0.4) Waddle Road / I 99 NB 322 EB Ramps SB approach LOS E (76.8) C (30.8) B (10.3) C (28.4) B (13.2) EBL queues 1741 512 505 412 433 NBT queues 756 451 377 454 368 SBL queues 393 621 805 495 403 SBT queues 712 713 761 369 628 Any V/C ratio > 1.0? YES EBL, SBL NO NO NO NO Overall LOS/Delay C (24.4) B (20.0) C (20.9) C (20.1) B (15.4) EB approach LOS D (53.5) E (55.1) E (55.1) D (45.5) D (37.2) WB approach LOS D (47.2) D (44.4) D (44.4) D (41.1) C (32.5) NB approach LOS C (22.4) A (3.0) A (3.1) C (21.2) C (20.4) SB approach LOS A (5.5) B (18.9) C (20.8) A (1.3) A (1.1) EBL queues 1355 349 359 332 266 Waddle Road / Colonnade Boulevard EBLT queues 1361 496 512 492 348 NBL queues 272 223 215 217 201 NBT queues 979 918 964 875 963 NBTR queues 371 382 353 355 363 SBL queues 181 218 196 203 224 SBT queues 502 767 784 618 752 SBR queues 145 694 547 465 575 Any V/C ratio > 1.0? NO YES SBT YES SBT NO NO