Truck Climbing Lane Traffic Justification Report

Transcription

1 ROUTE 7 (HARRY BYRD HIGHWAY) WESTBOUND FROM WEST MARKET STREET TO ROUTE 9 (CHARLES TOWN PIKE) Truck Climbing Lane Traffic Justification Report Project No , P 101 Ι UPC No Prepared by: Prepared for: Virginia Department of Transportation October 31, 2008 Revised February 15, 2009

2 Route 7 - Truck Climbing Lane Page 1 of 19 Table of Contents EXECUTIVE SUMMARY... 3 INTRODUCTION... 4 EXISTING TRAFFIC CONDITIONS... 5 Existing Speed Data... 7 Existing Peak Hour Traffic Volumes... 9 Existing Roadway Levels of Service WARRANT ANALYSIS AASHTO Climbing Lane Warrants For Multi-lane Highways Critical Length of Grade Service Flow Volumes along Route Operational Assessment Levels of Service Additional Analysis - Off Peak Period Results of Warrant Analysis THROUGH LANE ALTERNATIVE Additional Analysis Truck Climbing Lane vs. General Purpose Lane CRASH ANALYSIS CONCLUSIONS SUPPORTING DOCUMENTATION List of Figures FIGURE 1: LOCATION MAP OF THE STUDY CORRIDOR... 4 FIGURE 2: ROUTE 7 - LANE CONFIGURATIONS AND COUNT LOCATIONS... 6 FIGURE 3: EASTBOUND ROUTE 7 CUMULATIVE SPEED CURVE FOR ALL VEHICLES... 7 FIGURE 4: EASTBOUND ROUTE 7 CUMULATIVE SPEED CURVE FOR HEAVY VEHICLES... 8

3 Route 7 - Truck Climbing Lane Page 2 of 19 FIGURE 5: WESTBOUND ROUTE 7 CUMULATIVE SPEED CURVE FOR ALL VEHICLES... 8 FIGURE 6: WESTBOUND ROUTE 7 CUMULATIVE SPEED CURVE FOR HEAVY VEHICLES... 9 FIGURE 7: EASTBOUND ROUTE 7 HOURLY VOLUMES FIGURE 8: WESTBOUND ROUTE 7 HOURLY VOLUMES List of Tables TABLE 1: 2008 EXISTING LEVELS OF SERVICE FOR ROUTE TABLE 2: LEVELS OF SERVICE FOR ROUTE 7 WITH AN ADDITIONAL TRUCK CLIMBING LANE TABLE 3: LEVELS OF SERVICE FOR ROUTE 7 WITH AN ADDITIONAL THROUGH LANE TABLE 4: LEVELS OF SERVICE FOR ROUTE TABLE 5: ACCIDENT SUMMARY ALONG ROUTE 7 FROM AUG 2005 THROUGH AUG TABLE 6: SUMMARY OF LEVELS OF SERVICE FOR ROUTE 7 UNDER VARIOUS CONDITIONS List of Appendices Appendix A Traffic Count Data Information Appendix B Speed Count Data Information Appendix C Accident Data Information and Collision Diagrams Appendix D Highway Capacity Software Worksheets Appendix E AASHTO Geometric Design of Highways and Streets 2004 & Highway Capacity Manual 2000 Information

4 Route 7 - Truck Climbing Lane Page 3 of 19 EXECUTIVE SUMMARY The purpose of this study is to assess transportation improvements along Westbound Route 7 (Harry Byrd Highway) from the interchange of West Market Street to the interchange of Route 9 (Charles Town Pike) in Loudoun County, VA. Preliminary observations by Virginia Department of Transportation (VDOT) revealed that trucks are unable to maintain sufficient speeds within the study area for the upgrade climb in the westbound direction, resulting in slow and congested traffic. This traffic justification report was prepared to present the traffic operation and safety issues associated with truck performance along a 2.25-mile hilly segment of the study corridor. The methodology of the study included a warrant analysis based on American Association of State Highway and Transportation Officials (AASHTO) Greenbook guidelines for implementing a truck climbing lane along a multi-lane highway. The information used for the analysis included the existing roadway profile and traffic data. The existing traffic data (hourly volume by speed and class) from VDOT permanent count station along the study corridor was used for the analysis. According to the results of the warrant analysis, a truck climbing lane is warranted along Westbound Route 7. According to the preliminary conceptual plan, it is anticipated that a through travel lane will be added in the existing median of Route 7 (Harry Byrd Highway), and the existing right travel lane will be converted to a truck climbing lane from the West Market Street interchange to Route 9 (Charles Town Pike Interchange). A minimum four (4) foot wide outside paved shoulder adjacent to the truck climbing lane will be provided in conformance with AASHTO requirements. An additional analysis was also performed to identify any improvements in the roadway level of service due to the addition of a general purpose through lane instead of a truck climbing lane. In addition, the crash data along the study corridor was reviewed to identify any safety concerns along Westbound Route 7. Based on the results of the analysis, provision of the additional through lane would be a better investment for improving along Route 7 WB. However, a truck climbing lane would improve existing operations and could be considered as an interim improvement measure, if funding is not available for construction of an additional through lane.

5 Route 7 - Truck Climbing Lane Page 4 of 19 INTRODUCTION (RK&K) is supporting the Virginia Department of Transportation (VDOT) in assessing transportation improvements along Route 7 (Harry Byrd Highway) Westbound (WB), specifically the addition of a truck climbing lane between the West Market Street and Route 9 (Charles Town Pike) interchanges. The purpose of this report is to assess the traffic operation and safety issues associated with truck performance along a 2.25-mile hilly segment of Westbound Route 7 from the interchange of West Market Street to the interchange of Route 9 (Charles Town Pike). Along this segment of roadway, there are four intermediate access points (in addition to West Market Street and Route 9): Leeland Orchard Road, Fort Johnston Road, Farm Market Road, and Hidden Gap Road. Figure 1 presents a location map of the study corridor. Figure 1: Location Map of the Study Corridor Traffic volume, speed, and crash data were provided by VDOT for this study. According to VDOT observations, trucks are unable to maintain sufficient speeds within the study area for the upgrade climb in the westbound direction, resulting in slow and congested traffic. As an improvement measure, a truck climbing lane has been suggested to improve traffic operations and enhance safety by shifting larger slow-moving trucks to a dedicated lane. The proposed improvements would be accomplished by adding a through travel lane in the existing median of Route 7 (Harry Byrd Highway) and converting the existing right travel lane to a truck climbing lane from the West Market Street interchange to Route 9 (Charles Town Pike Interchange). It is recommended that a minimum of four (4) foot wide outside paved shoulder adjacent to the truck climbing lane be provided in conformance with AASHTO requirements due to the limited existing outside shoulder width in some locations. The typical section for the proposed improvements with the four (4) foot wide outside paved shoulder is included in the Appendix A.

6 Route 7 - Truck Climbing Lane Page 5 of 19 EXISTING TRAFFIC CONDITIONS Route 7 (Harry Byrd Highway) is an east-west roadway connecting Winchester to the west and Alexandria to the east. The roadway is classified as a Rural Principal Divided Arterial and is a four-lane divided highway with a posted speed limit of 55 mph within the project vicinity. The subject Route 7 WB within the study length has an assumed rolling terrain type classification with a maximum upgrade of approximately 7.0% which begins approximately 1,200 feet west of the West Market Street on-ramp and extends for approximately 1,000 feet. In general, the existing profile for Route 7 can be described as being on a continuous climb, beginning at West Market Street interchange and ending just prior to the Route 9 interchange. The existing median width varies but measures approximately 60 feet from inside edge of travel lane to inside edge of travel lane on either approach. Traffic volume and speed data by vehicle classification was provided by VDOT for the Route 7 corridor. The data provided was recorded at two VDOT permanent count stations each along eastbound and one westbound direction. Figure 2 shows the lane configurations for Route 7 from West Market Street to the Route 9 interchange including the acceleration and deceleration lanes to and from the crossover connections. Figure 2 also presents the approximate locations of VDOT permanent count stations along Route 7 Eastbound (EB) and Westbound (WB). Appendix A contains the traffic volumes recorded at all the count stations. Observations of the study area were performed by RK&K during the AM and PM peak periods on Wednesday, October 22 nd, These observations were performed to identify distinctive travel patterns, any unusual incidents or operations, and to assess the terrain and pedestrian activity levels. The field observations are summarized as follows: Route 7 EB is the peak direction of travel during the AM peak period (6AM to 9AM). Route 7 WB is the peak direction of travel during the PM peak period (4PM to 7PM). The upgrade for Route 7 WB begins approximately 800 feet east of the West Market Street interchange on-ramp to Route 7 WB and crests approximately 1,200 feet east of Route 9 interchange off-ramp. The congestion/delays along the Route 7 WB appears to be influenced by both the West Market Street on-ramp merge and the truck traffic on the Route 7 WB upgrade east of the West Market Street interchange. It was observed that the truck traffic was passing through the study corridor without using any of the four (4) exiting crossovers. Thus, the predominant movements associated with the truck climbing lane should be as a through movement. However, limited truck traffic (buses, garbage, and delivery trucks) probably uses the crossovers to access the residential developments along Route 7. Provisions for this use should be included in the redesign of the crossovers. No pedestrian activity was observed during the field review.

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8 Route 7 - Truck Climbing Lane Page 7 of 19 Existing Speed Data The speed data provided by VDOT consisted of hourly counts by vehicle classification, hourly counts by speed of the vehicles, and hourly counts by vehicle classification by speed of the vehicles for each count location along Route 7 with in the study area. Based on the data from VDOT s permanent count location, RK&K has calculated the 85 th percentile speed for both eastbound and westbound directions. The 85 th percentile speed is a speed at or below which 85 percent of people drive at any given location under good weather and visibility conditions and may be considered as the maximum safe speed for that location. A cumulative speed distribution curve was generated to present the 85 th percentile speed for all vehicles including heavy vehicles along Route 7 EB and WB within the study area. Figures 3 through 6 present the cumulative speed distribution curves for Route 7. For this study, vehicle classifications Class 4 through 13 were considered as heavy vehicles / trucks. The 85 th percentile speed for Route 7 EB for all vehicles is estimated to be approximately 68mph, whereas, for EB trucks, the 85 th percentile speed was estimated to be 63mph. Similarly, for WB Route 7, the 85 th percentile speeds for all vehicles and trucks were estimated to be 65mph and 63mph. The relevant speed data is included in the Appendix B. Cumulative Speed Distribution Curve for All Vehicles Eastbound Route 7 All Vehicle Count Percentile 105% 100% 95% 90% 85% 80% 75% 70% 65% 60% 55% 50% 45% 40% 35% 30% 25% 20% 15% 10% 5% 0% Speed (mph) Cumulative Speeds Figure 3: Eastbound Route 7 Cumulative Speed Curve For All Vehicles

9 Route 7 - Truck Climbing Lane Page 8 of 19 Cumulative Speed Distribution Curve for Heavy Vehicles Eastbound Route 7 Heavy Vehicle Count Percentile 105% 100% 95% 90% 85% 80% 75% 70% 65% 60% 55% 50% 45% 40% 35% 30% 25% 20% 15% 10% 5% 0% Speed (mph) Cumulative Speeds Figure 4: Eastbound Route 7 Cumulative Speed Curve For Heavy Vehicles Cumulative Speed Distribution Curve for All Vehicles Westbound Route 7 All Vehicle Count Percentile 105% 100% 95% 90% 85% 80% 75% 70% 65% 60% 55% 50% 45% 40% 35% 30% 25% 20% 15% 10% 5% 0% Speed (mph) Cumulative Speeds Figure 5: Westbound Route 7 Cumulative Speed Curve For All Vehicles

10 Route 7 - Truck Climbing Lane Page 9 of 19 Cumulative Speed Distribution Curve for Heavy Vehicles Westbound Route 7 Heavy Vehicle Count Percentile 105% 100% 95% 90% 85% 80% 75% 70% 65% 60% 55% 50% 45% 40% 35% 30% 25% 20% 15% 10% 5% 0% Speed (mph) Cumulative Speeds Figure 6: Westbound Route 7 Cumulative Speed Curve For Heavy Vehicles Existing Peak Hour Traffic Volumes VDOT has provided traffic volumes (hourly and daily) for Route 7 from the permanent traffic count station on Route 7 EB and WB. The approximate locations of the permanent traffic count stations are shown in Figure 2. Even though the count station on the WB approach is not located at the steepest upgrade (it is located west of the West Market Street interchange), we assumed that the difference between the truck volumes at the permanent count station and at the steepest upgrade is negligible since no trucks were observed entering from or exiting to the crossover connections during the field review. RK&K has selected typical weekdays (Tuesday, Wednesday, and Thursday) to determine an average twenty-four (24) hour traffic volume for a typical weekday based on one-month data (from September 9, 2008 to October 9, 2008). To review how the hourly traffic is varying through out the day, two diurnal variation curves were generated for Route 7 EB and WB. Figures 7 and 8 present the diurnal curves for Route 7 Eastbound and Westbound, respectively. A review of Figures 7 and 8 indicate that during the AM peak period (between 6AM to 9AM), Route 7 EB hourly volumes are higher than the acceptable/desired LOS D service volume of 3,400 vehicles per hour per approach. Similarly, during PM peak period (between (4PM to 7PM), the Route 7 WB hourly volume is greater than 3,400 vehicles per hour per approach. This suggests that the roadway is not of sufficient capacity to support the current traffic condition. Appendix A contains the summary of traffic volumes used in the analysis.

11 Route 7 - Truck Climbing Lane Page 10 of 19 Diurnal Variation of a Typical Weekday for Eastbound Rte 7 Traffic Counts 4,400 4,200 4,000 3,800 3,600 3,400 3,200 3,000 2,800 2,600 2,400 2,200 2,000 1,800 1,600 1,400 1,200 1, Hours in a Day Passenger Vehicles Heavy Vehicles TOTAL Figure 7: Eastbound Route 7 Hourly Volumes Diurnal Variation of a Typical Weekday for Westbound Rte 7 Traffic Counts 4,400 4,200 4,000 3,800 3,600 3,400 3,200 3,000 2,800 2,600 2,400 2,200 2,000 1,800 1,600 1,400 1,200 1, Hours in a Day Passenger Vehicles Heavy Vehicles TOTAL Figure 8: Westbound Route 7 Hourly Volumes

12 Route 7 - Truck Climbing Lane Page 11 of 19 Existing Roadway Levels of Service Levels of service were calculated for the existing conditions using the Highway Capacity Manual and HCS+ Software (latest edition) for Route 7. The Multi-Lane Highway module was used with the peak hour volumes shown in Figures 7 and 8, along with the actual grades, percent of trucks, and speeds provided by VDOT and verified with field observations. The terrain was assumed to be rolling terrain for the study corridor. The peak hour factor was assumed to be 0.90 for each direction and the truck percentages were calculated from the hourly traffic data by classification. Vehicles of Class 1 through Class 3 were assumed to be passenger cars, whereas vehicles of Class 4 through 13 were grouped together and considered as heavy trucks. Vehicle Classes 14 and 15 were not considered in the analysis since they were classified as unknown vehicle types. The results of the HCS analysis are summarized below and the worksheets are included in the Appendix D. Table 1: 2008 Existing Levels of Service for Route 7 Direction AM PM Eastbound F B Westbound A F As shown in the table above and as indicated in Figures 7 and 8, the level of service falls below the acceptable/desired LOS D threshold for the study corridor. Additional capacity is required to improve the level of service along Route 7.

13 Route 7 - Truck Climbing Lane Page 12 of 19 WARRANT ANALYSIS AASHTO Climbing Lane Warrants For Multi-lane Highways According to the AASHTO Geometric Design of Highways and Streets 2004 (Greenbook), if one of the following principal considerations is satisfied, a truck climbing lane is warranted on a multi-lane highway. Critical Length of Grade - Length of grade exceeds the critical length of grade as determined by AASHTO Exhibit Service Flow Volumes - Service flow volume is greater than 1,000 vphpl, but less than 1,700 vphpl Operational Assessment - Level of Service - Existing level of service exceeds LOS D and would be improved one grade level with the addition of a truck climbing lane Critical Length of Grade According to AASHTO, the critical length of grade is the length of a particular upgrade that reduces the speed of low-performance trucks by 10 mph below the average running speed of the remaining traffic. The critical length is determined by using Exhibit 3-59 from the AASHTO Greenbook. If the critical length of grade is less than the length of grade being evaluated, consideration of a climbing lane may be warranted. For the current project along Route 7 WB, it was observed that the steepest upgrade (approximately 7 %) exists 1,200 feet west of West Market Street on-ramp, according to the existing profile data indicated on the Route 7 record plans dated 1973 received by VDOT. By using the Exhibit 3-59, for an upgrade of approximately 7% for a 10mph reduction in truck speed, the critical length of grade was determined to be 700 feet. To determine the actual length of the upgrade, the existing roadway profile was used. At the point of steepest upgrade (approximately 7%), the length of tangent measures approximately 1000 feet. As such, the actual length exceeds the critical length of grade. Hence, this criterion of the AASHTO truck climbing warrant is met. Service Flow Volumes along Route 7 According to AASHTO, the need for a truck climbing lane on a multi-lane highway is not generally met if the volumes on the facility are less than 1,000 vehicles per hour per lane. This is because sufficient capacity exists for autos to bypass trucks in the left lane without significant delay. When volumes exceed 1,700 vehicles per hour per lane, the capacity of the multi-lane facility is approached, and provision of additional through lane capacity may be a better investment than providing a truck climbing lane. Therefore, truck climbing lanes could be a good investment along segments where the volumes are under 1,700 vphpl but exceed 1,000 vphpl.

14 Route 7 - Truck Climbing Lane Page 13 of 19 From Figures 7 and 8 and the results of the HCS analysis in Table 1, the PM peak hour volume along Westbound is not only higher than 1,000 vphpl but also higher than 1,700 vphpl. So an additional through lane would be a better option to improve capacity when compared to a truck climbing lane. Since the traffic volumes exceed the desirable capacity range during peak periods, a truck climbing lane may not be the best overall solution. Instead, consideration of additional through lane capacity is suggested by AASHTO. Operational Assessment Levels of Service According to AASHTO, climbing lanes should not generally be considered unless the level of service (LOS) for the upgrade is equal to or greater than LOS D. In addition, climbing lanes would be a good solution for a facility where the addition of this treatment results in a one-gradelevel improvement in operations, therefore avoiding a reduction of two or more levels of service. As shown in Table 1, the existing level of service for the Route 7 WB exceeds LOS D during PM peak hour. Additional HCS analysis was performed to determine the levels of service with an assumed truck climbing lane, resulting in an improvement of at least one level of service LOS E. Table 2 provides a summary of the levels of service for Route 7 WB with an additional truck climbing lane. Table 2: Levels of Service for Route 7 with an Additional Truck Climbing Lane Direction AM PM Eastbound F A Westbound A E Based on these results in Table 2, there is an improvement in level of service during PM peak hour along Westbound Route 7 from LOS F to LOS E with the addition of a truck climbing lane. In conclusion, this warrant is met. Assumption for the Operational Assessment The multi-lane analysis module of the Highway Capacity Software (HCS+) program doesn t allow coding/inputting of the special purpose travel lanes reserved for a single vehicle type, such as a truck climbing lane. So, in order to perform the operational assessment along the study corridor with an additional truck climbing lane, as explained below. For the analysis scenario where two general purpose lanes and one truck climbing lane were considered, there were coded in as two general purpose lanes with zero truck traffic which in turn assumes that all the trucks would be using the additional truck climbing lane. Since the percentage of trucks along Route 7 WB direction is only 1% of the total peak hour traffic (worst case scenario PM peak), no operational challenges are anticipated due to this assumption.

15 Route 7 - Truck Climbing Lane Page 14 of 19 Additional Analysis - Off Peak Period The three warrants for a truck climbing lane on a multilane highway were also tested under offpeak conditions along Route 7 westbound and the results are shown below. This section was provided for informational purposes only. Critical Length of Grade: The criterion for this warrant is not affected by the time of the day. Under the existing conditions of the project, this warrant is met. Service Flow Volumes along Route 7: Figure 8 was reviewed further to determine that, along Route 7 WB for the following time periods during the day, 2PM to 3PM and 6PM to 8PM, the traffic volumes per lane were higher than 1,000vphpl but not exceeding 1,700vphpl; hence, the warrant is met for these time periods. Operational Assessment Levels of Service: The existing level of service along Westbound Route 7 was determined using HCS analysis. It was determined that under off-peak conditions, the roadway performs at LOS D or better. So, according to the current warrant criterion, the warrant is not met. Results of Warrant Analysis The results of warrant analysis are summarized as follows: Length of grade exceeds the critical length of grade as determined by AASHTO Warrant is Met Service flow volume is greater than 1,000 vphpl, but less than 1,700 vphpl Per lane volumes are exceeded during peaks consider additional through lane capacity. Existing level of service exceeds LOS D and would be improved one grade level with the addition of a truck climbing lane Warrant is Met.

16 Route 7 - Truck Climbing Lane Page 15 of 19 THROUGH LANE ALTERNATIVE Considering the high directional volumes during the peak hours that are above capacity levels, HCS analysis was performed to identify any improvements in the levels of service due to addition of a general purpose through lane instead of a truck climbing lane. The results of the HCS analysis with an additional through lane are presented in Table 3. Table 3: Levels of Service for Route 7 with an Additional Through Lane Direction AM PM Eastbound C A Westbound A C Based on these results in Table 3, there is an improvement in level of service during PM peak hour from LOS F to LOS C with the addition of a general purpose through lane. This shows that addition of a through lane is a better option than providing a truck climbing lane along Westbound Route 7. Additional Analysis An additional HCS Multi-lane analysis was performed for the Westbound Route 7 segment with the highest upgrade of 6.97% (limited to 6% in HCS) just past the West Market Street on-ramp. The results of the HCS analysis with options of a truck lane and an additional through lane are presented in Table 4. Table 4: Levels of Service for Route 7 with an Upgrade of 6% With Existing Two Travel lanes With an Additional Truck Climbing Lane With an Additional Through Lane Direction AM PM AM PM AM PM Eastbound* F B F A C A Westbound A F A E A C * Grade percentage not available for Eastbound so rolling terrain was assumed From the results shown in Table 4, it is evident that there is one grade change in level of service with an additional truck climbing lane at the highest upgrade. However, an additional general purpose through lane would significantly improve operational conditions along Westbound Route 7. Truck Climbing Lane vs. General Purpose Lane There is no difference between a truck climbing lane and a general purpose lane in terms of functionality. However, a truck climbing lane will be provided with special signing and striping per AASHTO and MUTCD guidelines. This study does not include an in-depth comparison of

17 Route 7 - Truck Climbing Lane Page 16 of 19 the implications of introducing a truck climbing lane or a general purpose lane along westbound Route 7. However, based on preliminary research, the following impacts were summarized. The vehicles accessing Route 7 westbound at the crossovers might experience delays due to the additional lane, especially the left-turning vehicles, which need to find an adequate gap to cross three lanes of traffic instead of two (existing geometry) before stopping at the median opening. This also causes a safety concern. Some of the mitigation measures that would be needed due to a new truck climbing lane or a general purpose lane include: restriction of left-turn movements at one or more crossovers, complete closure or one or more crossovers, and signalization for one or more crossovers. These measures could improve safety conditions along the study corridor. However, a detailed study needs to be performed to determine the exact mitigation measures.

18 Route 7 - Truck Climbing Lane Page 17 of 19 CRASH ANALYSIS Crash data was provided by VDOT for a period of three (3) years between August 31, 2005 and August 31, 2008 along Route 7 from the W. Market Street interchange to the Route 9 interchange. The crash data was generated by VDOT using the HTRIS Accident Subsystem. The total number of accidents recorded for the study period was 161, which include one (1) fatal accident and 50 injury accidents. A total of 110 accidents resulted in property damage only. No pedestrian crashes were reported during the study period. The HTRIS summary for the study corridor indicates that the average accident rate for the study corridor was estimated to be 97 with a death rate of and injury rate of 36. A total of 292 vehicles were involved in the total accidents. Thirteen (8%) of accidents were recorded on wet pavement and 45 (27%) of accidents were recorded in dark conditions without lighting. The predominant types of accidents reported were rear-end (76), fixed object (32), hitting deer (20), sideswipe (15), and angle (11) accidents. The high number of the rear-end accidents on a limited access highway indicates that there might be a possibility of traffic congestion in the area. In addition, it is noted that 94 vehicles out of the total were involved in vehicle maneuvers such as slowing, stopping, and starting in traffic. Also, 15 (5%) trucks were involved in the total accidents. Out of the 292 total vehicles, 161 vehicles were driving in the eastbound direction and 120 vehicles were driving in the westbound direction. According to the collision diagrams of the study corridor provided by VDOT, 72 accidents were recorded along Westbound Route 7. The majority of the accidents were rear-end and hit fixed object off road type accidents. Both types of crashes seemed to be scattered all along the study corridor, making it difficult to identify any specific accident-prone locations. However, the significantly high number of rear-end crashes indicates congestion. The fatal accident occurred between the Farm Market Road and Hidden Gap Road. Due to the limited detail of the collision diagrams, truck specific conclusions could not be made. However, it was evident that along Route 7 WB, around the steepest location (near Lee Orchard Street), a total of 7 (10% of WB total) accidents were recorded. Table 5 presents the summary accidents along Route 7 Westbound and Eastbound from August 2005 through August Table 5: Accident Summary Along Route 7 from Aug 2005 through Aug 2008 Type of Accident Route 7 WB EB Rear-End Angle 7 5 Sideswipe - Opp. Direction 2 1 Sideswipe - Same Direction 9 9 Fixed Object - Off Road 22 9 Ran Off Road - Non Collision 3 4 Backed Into 0 1 Deer Accidents 3 15 Total The provision of a truck climbing lane along the Westbound Route 7 may improve the performance of the study corridor by reducing the delay caused by traffic congestion. The collision diagrams along the study corridor provided by VDOT are included in Appendix C.

19 Route 7 - Truck Climbing Lane Page 18 of 19 CONCLUSIONS To achieve the study purpose of assessing the traffic operations and safety issues associated with truck performance along a 2.25-mile hilly segment of Route 7 WB from the interchange of West Market Street to the interchange of Route 9 (Charles Town Pike), RK&K used the truck climbing lane warrant methodology for multilane highways described in AASHTO Geometric Design of Highways and Streets 2004 (Greenbook). The warrants were tested against the existing conditions (traffic and speed data by vehicle classification) of the study corridor. The results of the warrant analysis are as follows: Length of grade exceeds the critical length of grade as determined by AASHTO Warrant is Met Service flow volume is greater than 1,000 vphpl, but less than 1,700 vphpl Per lane volumes are exceeded during peaks consider additional through lane capacity. Existing level of service exceeds LOS D and would be improved one grade level with the addition of a truck climbing lane Warrant is Met Based on the above discussions and analysis provided, provision of a truck climbing lane would improve operations along WB Route 7. However, considering the high PM peak hour volume for WB Route 7, additional analysis was performed to identify if an additional through lane would serve as a better option than a truck climbing lane. The results of the HCS analysis are summarized in Table 6. Table 6: Summary of Levels of Service for Route 7 under Various Conditions Direction Eastbound Westbound Eastbound Westbound Direction Two General Purpose Lanes Lane Configuration Two General Purpose Lanes + One Truck Climbing Lane Three General Purpose Lanes Rolling Terrain AM F F C PM B A A AM A A A PM F E C 7% Upgrade AM F F C PM B A A AM A A A PM F E C Based on the above analyses, provision of additional through lane would be a better investment for improving along Westbound Route 7. However, a truck climbing lane would improve existing operations (from LOS F to LOS E) and could be considered as an interim improvement measure if funding is not available for construction of an additional through lane.

20 Route 7 - Truck Climbing Lane Page 19 of 19 SUPPORTING DOCUMENTATION Data provided by VDOT: The following data provided by VDOT is attached in the appendix. Speed data by vehicle type per hour for 3 days Hourly Counts by vehicle classification from Sept 9, 2008 to Oct 9, 2008 Daily Counts by vehicle classification from Sept 9, 2008 to Oct 9, 2008 Accident Information for 3 year period (Aug 31, 2005 to Aug 31, 2008) Collision Diagrams for the study corridor (Aug 31, 2005 to Aug 31, 2008) References: The exhibits and referenced material from the following sources are attached in the Appendix E. AASHTO- Geometric Design of Highways and Streets 2004 (Greenbook) Highway Capacity Manual 2000.