Project Evaluation Report

Transcription

1 Project Evaluation Report Prepared for: Georgia Regional Transportation Authority Prepared by: TransCore 192 Technology Parkway, Suite 500 Norcross, Georgia June 30, 2010

2 TABLE OF CONTENTS EXECUTIVE SUMMARY ATLANTA SMART CORRIDOR BACKGROUND INTRODUCTION PROJECT DESIGN SCATS and Presence Detection Transit Signal Priority and ADA Upgrades EVALUATION PLAN EVALUATION SCHEDULE EVALUATION METHODOLOGIES SCATS EVALUATION PLAN Travel Time and Delay Economic Indicators Air Quality TSP EVALUATION PLAN EVALUATION RESULTS SCATS EVALUATION RESULTS Travel Time Vehicle Delay Vehicle Stops Environmental Pollution Emissions Project Benefits Annual Costs Benefit/Cost Analysis Summary TRANSIT SIGNAL PRIORITY EVALUATION RESULTS Average Transit Travel Time Standard Deviation of Transit Travel Time Stop Rate Average Stop Time On-Time Performance Level of Service (LOS) Summary INSTITUTIONAL AND TECHNICAL ISSUES: LESSONS LEARNED INSTITUTIONAL ISSUES TECHNICAL ISSUES CONCLUSION APPENDIX A: AVERAGE TRANSIT TRAVEL TIME AVERAGE TRANSIT TRAVEL TIME (BEFORE) Before Thursday, 11/19/ Before Tuesday, 12/15/ Before Wednesday, 12/16/ Before Thursday, 12/17/ AVERAGE TRANSIT TRAVEL TIME (AFTER) After Wednesday, 06/09/ Project Evaluation Report ii June 30, 2010

3 5.2.2 After Thursday, 06/10/ After Tuesday, 06/15/ After Wednesday, 06/16/ After Thursday, 06/17/ APPENDIX B: INTERSECTION STOP RATE AND TIME BY DAY INTERSECTION STOP RATE AND TIME BY DAY (BEFORE) Before Thursday, 11/19/ Before Tuesday, 12/15/ Before Wednesday, 12/16/ Before Thursday, 12/17/ INTERSECTION STOP RATE AND TIME BY DAY (AFTER) After Wednesday, 06/09/ After Thursday, 06/10/ After Tuesday, 06/15/ After Wednesday, 06/16/ After Thursday, 06/17/ APPENDIX C: ON TIME PERFORMANCE LOS BY DAY ON TIME PERFORMANCE LOS BY DAY (BEFORE) ON TIME PERFORMANCE LOS BY DAY (AFTER) Project Evaluation Report iii June 30, 2010

4 LIST OF FIGURES FIGURE 1-1: ATLANTA SMART CORRIDOR LOCATION MAP FIGURE 2-1: CCT ROUTE 10 MAP FIGURE 3-1: NORTHBOUND TRAVEL TIME ON SMART CORRIDOR FIGURE 3-2: SOUTHBOUND TRAVEL TIME ON SMART CORRIDOR FIGURE 3-3: NORTHBOUND TOTAL TRAVEL TIME FIGURE 3-4: SOUTHBOUND TOTAL TRAVEL TIME FIGURE 3-5: STANDARD DEVIATION OF NB TRAVEL TIME ON SMART CORRIDOR FIGURE 3-6: STANDARD DEVIATION OF SB TRAVEL TIME ON SMART CORRIDOR FIGURE 3-7: STANDARD DEVIATION OF NB TOTAL TRAVEL TIME FIGURE 3-8: STANDARD DEVIATION OF SB TOTAL TRAVEL TIME LIST OF TABLES TABLE 3-1: BEFORE AND AFTER TRAVEL TIME COMPARISON TABLE 3-2: BEFORE AND AFTER DELAY COMPARISON TABLE 3-3: BEFORE AND AFTER VEHICLE STOPS COMPARISON TABLE 3-4: COMPARISON OF CO EMISSIONS TABLE 3-5: COMPARISON OF NOX EMISSIONS TABLE 3-6: COMPARISON OF VOC EMISSIONS TABLE 3-7: COMPARISON OF FUEL CONSUMPTION TABLE 3-8: ANNUAL IMPROVEMENT COST BENEFITS TABLE 3-9: EQUIVALENT ANNUAL COST OF SCATS TABLE 3-10: SMART CORRIDOR BENEFIT COST ANALYSIS TABLE 3-11: BEFORE STUDY TRANSIT TRAVEL TIME SUMMARY TABLE 3-12: AFTER STUDY TRANSIT TRAVEL TIME SUMMARY TABLE 3-13: AVERAGE TRANSIT TRAVEL TIME COMPARISON TABLE 3-14: BEFORE STUDY STANDARD DEVIATION OF TRANSIT TRAVEL TIME TABLE 3-15: AFTER STUDY STANDARD DEVIATION OF TRANSIT TRAVEL TIME TABLE 3-16: STANDARD DEVIATION OF TRANSIT TRAVEL TIME COMPARISON TABLE 3-17: INTERSECTION STOP RATE COMPARISON TABLE 3-18: BEFORE STUDY INTERSECTION STOP RATE AND TIME TABLE 3-19: AFTER STUDY INTERSECTION STOP RATE AND TIME TABLE 3-20: COMPARISON OF AVERAGE INTERSECTION STOP TIME TABLE 3-21: BEFORE STUDY DEPARTURES AND CORRESPONDING LOS TABLE 3-22: AFTER STUDY DEPARTURES AND CORRESPONDING LOS Project Evaluation Report iv June 30, 2010

5 EXECUTIVE SUMMARY The Project, which is a metro Atlanta traffic management project managed by the Georgia Regional Transportation Authority, (GRTA), is an innovative approach to managing traffic and transit operations in one of the Atlanta region s most congested corridors. The Smart Corridor is along US 41/Cobb Parkway/Northside Parkway from Howell Mill Road in the City of Atlanta to Spinks Drive in the City of Marietta and is approximately 8.2 miles. The Smart Corridor consists of eleven City of Atlanta intersections, eleven Cobb County intersections, and seven City of Marietta intersections. The project included the installation of SCATS (Sydney Coordinated Adaptive Traffic System, Transit Signal Priority (TSP), and intersection improvements. The intersection improvements included ADA (Americans with Disabilities Act) pedestrian facilities, detectors, controller and cabinet upgrades. Because of the number of improvements required, this portion of the project was let as a separate GDOT construction contract. Once the intersection improvements were complete and SCATS and TSP were operational, a before and after study was conducted to evaluate the effectiveness of both SCATS and TSP. For the SCATS study, travel time and delay were recorded from a probe vehicle traveling at the median speed of the traffic flow along the project corridor. The device used to collect and analyze the travel time and delay data was a lap top computer in conjunction with a GPS Travel Time Data Collector and PC Travel software. When the data collected by the GPS data collector was analyzed using the PC Travel software, travel time, delay, and stop statistics could be calculated. The TSP study data was gathered by an individual riding the CCT Route #10 Bus and collecting timestamp and delay data at various bus stops and intersections. Five performance measures were evaluated, including average travel time, standard deviation of average travel time, intersection stop rate, average intersection stop time, and on-time performance level of service. Data from the SCATS evaluation shows that travel time, vehicle delay, and vehicle stops have all been significantly reduced throughout the corridor, with the greatest reduction in the southbound direction. NOx and VOC emissions have been reduced since vehicles are able to maintain a more constant speed while traveling through the corridor. The reduced delay and vehicle stops also contributes to lower fuel consumption, since vehicles are not idling and accelerating as often. The TSP study results showed that with the addition of SCATS and TSP, the average southbound transit travel times decreased, while the average northbound transit travel times increased. The standard deviation of transit travel time increased in the northbound direction, meaning that there was a wider range of travel times observed in the after study, while it decreased in the southbound direction. The average stop rate throughout the corridor decreased slightly in the northbound direction and remained roughly the same in the southbound direction. When looking at the average of all intersections, the average stop time decreased slightly in the northbound direction and decreased substantially in the southbound direction. This result is expected with the addition of SCATS and TSP, which should both work together to reduce the duration of stop delay at the intersections. The addition of SCATS and TSP did not seem to have much of an impact on the on-time performance LOS; rather, the biggest LOS improvement would come from ensuring that the buses do not leave the scheduled stops ahead of their scheduled time. Based on the results of the travel time analysis, it can be concluded that the implementation of the Smart Corridor SCATS system has greatly benefited the traffic flow throughout the area. The implementation of the SCATS system has produced an annual savings of $5,938,646 in the form of reduced travel time and fuel consumption. The improved timing plans for the Smart Corridor have benefit/cost ratios ranging from 23.2:1 to 28.2:1, which is equivalent to paying for themselves every 9 to 10 workdays. The studies also show that there were certain transit benefits derived from the addition of SCATS and TSP; however, data sampling for these studies was very small, and a larger study would likely produce more statistically Project Evaluation Report 1 June 30, 2010

6 significant results. The busiest intersection along the corridor, Windy Hill Rd., did not have SCATS software installed during the after testing period, so an improvement at that location would likely further reduce the delay and overall travel times along the corridor. Project Evaluation Report 2 June 30, 2010

7 1. ATLANTA SMART CORRIDOR BACKGROUND 1.1 Introduction Cobb Parkway/Northside Parkway is one of the seventy-three corridors included in the metro Atlanta Congestion Management System as needing improvement. The Project, which is a metro Atlanta traffic management project managed by the Georgia Regional Transportation Authority, (GRTA), is an innovative approach to managing traffic and transit operations in one of the Atlanta region s most congested corridors. The Smart Corridor is along US 41/Cobb Parkway/Northside Parkway from Howell Mill Road in the City of Atlanta to Spinks Drive in the City of Marietta. A Federal funding grant of $827,318 for the project came from the Intelligent Transportation Systems (ITS) Integration component of the ITS Deployment Program as defined in Section 5208 of the Transportation Equity Act for the 21st Century (TEA-21). This funding has been matched by $60,000 in local funding by GRTA and an additional local match of $1,898,641 by the Georgia Department of Transportation (GDOT), the City of Marietta, and Cobb Community Transit (CCT). GRTA, in partnership with regional agencies, had developed a plan to use these funds, and formalized it in a Partnership Agreement with the Federal Highway Administration (FHWA). Additionally, GRTA and GDOT entered into a Memorandum of Understanding (MOU), which defines each party s roles and responsibilities with respect to the Project. GRTA spearheaded the Smart Corridor project implementation. This project is a multi-jurisdictional effort involving the following other primary stakeholders: Federal Highway Administration (FHWA); GDOT; Cobb County (including Cobb Community Transit); City of Atlanta; and, City of Marietta. Five primary stakeholder meetings were conducted to discuss candidate technologies for implementation within the. Based on discussion involving the stakeholders, the consensus was that the following technologies would provide the most benefit to the corridor and were selected for deployment: Technology 1 Adaptive Traffic Signal Control System Technology 2 Transit Signal Priority These technologies and other project elements were summarized in a Project Concept Report submitted to and approved by GDOT in During the same year, the Project ITS Architecture was developed, conforming to the approved Atlanta Regional ITS Architecture and the guidelines set forth by the National ITS Architecture, and submitted to the Atlanta Regional Commission for inclusion in the Atlanta Regional ITS Architecture. As part of the project, design plans and specifications for transit signal priority, presence detection (inductive loops and video detection cameras), and intersection upgrades were produced as well as the procurement and installation of the adaptive signal control hardware/software (SCATS - Sydney Coordinated Adaptive Traffic System) at 18 intersections along the corridor. Project Evaluation Report 1-1 June 30, 2010

8 1.2 Project Design The Smart Corridor project begins in Cobb County on US41/Cobb Parkway at Spinks Drive and extends south to Howell Mill Road on Northside Parkway in Fulton County (see Figure 1-1). The length of this corridor is approximately 8.2 miles. The Smart Corridor consists of eleven City of Atlanta intersections, eleven Cobb County intersections, and seven City of Marietta intersections. It was determined in conjunction with FHWA (Federal Highway Administration) that ADA and intersection upgrades would be required as part of the Atlanta Smart Corridor Project. In order to perform the work associated with these additional tasks as well as the necessary intersection upgrades, GDOT let and executed another project Traffic Signal Upgrades within GRTA Smart Corridor, based on the design plans. These intersection upgrades included new traffic signal controller cabinets, traffic signal heads, pedestrian signals, SCATS compatible detection (in each lane), etc. Pedestrian accommodations meeting pedestrian/ada standards were provided at each project intersection. Typical pedestrian accommodations needed at each project intersection included crosswalks, stop bars, sidewalks and ramps, cutthroughs at existing islands/medians, pedestrian signal heads, pedestrian push button stations, and stop for pedestrian signs (R560-5). Based on stakeholder discussions, the consensus was that the following technologies would provide the most benefit to the corridor and were selected for deployment: Technology 1 Adaptive Traffic Signal Control System Figure 1-1: Location Map Technology 2 Transit Signal Priority Adaptive traffic signal control is "smart" signal control that uses real time intersection data obtained from sensors at the intersection to determine the most appropriate timing of the signal. With this type of Project Evaluation Report 1-2 June 30, 2010

9 control, traffic signal operations can adapt to rapidly changing traffic conditions, such as those caused by incident traffic diversion. Sydney Coordinated Adaptive Traffic System (SCATS) was the technology selected for this application. It is an adaptive traffic control system that monitors traffic and adapts in real-time to traffic changes. It applies a real time, predictive strategy to the traffic signal timing plan based on intersection data and user defined parameters. It adjusts signal timing parameters in response to variations in traffic demand and system capacity. Logic and algorithms in the system s controllers and traffic control computer analyze real time data from vehicle detectors, such as inductive loops located at each intersection stop bar, to produce signal timings, which are suitable for the prevailing traffic conditions. The SCATS system fulfilled all of the functional requirements of the Project. In addition, Cobb County had also recently let a contract for installation of SCATS at all 70 intersections within the Cumberland CID area, including all Cobb DOT-maintained intersections on Cobb Parkway south of the City of Marietta. The installation of SCATS in the City of Atlanta and the City of Marietta as part of the Project built upon what was implemented as part of the Cobb County project, expanding the adaptive control north and south of the Cobb County implementation. Deploying transit signal priority (TSP) technology is an effective means of achieving short-term, low-cost improvement in bus operations within the project corridor. TSP consists of a forward-aimed transmitter installed on each Cobb Community Transit (CCT) bus, a receiver mounted on a mast arm, span wire, or pole at each bus approach to the signalized intersections, and the associated processor installed in the traffic signal cabinets for communication with the traffic signal controller. The bus priority processor decodes the bus signal, validates it, and then determines if bus priority can be achieved based on the following logic: If the traffic signal is currently green, and will likely still be green at the time of the bus s arrival, then bus priority is not needed. If the traffic signal is currently green, but would likely change to red by the time of the bus s arrival, bus priority attempts to extend that green to coincide with the bus s arrival, within preprogrammed extension limits. If the traffic signal is currently red, the bus priority attempts to have the green signal begin early, to better match the bus s arrival, within pre-programmed extension limits. The technology selected for this application is 3M Opticom. The Opticom system works with the traffic signal controller to provide pre-emption and green time extension for high priority and low priority vehicles within user defined parameters. The Opticom system fulfilled all of the functional requirements of the project and has proven itself as a transit signal priority system. It was first developed over 25 years ago and continues to maintain system compatibility between different equipment versions in order to protect the user s investment. The City of Marietta currently uses Opticom technology for its emergency vehicle pre-emption system. Using this same technology for the TSP system was very cost effective because the detectors were already in place at the Smart Corridor traffic signals within the City of Marietta SCATS and Presence Detection As part of the Project, adaptive traffic signal control hardware and presence detection have been installed at selected intersections within the, including seven intersections within the City of Marietta and eleven intersections within the City of Atlanta. presence detection is required on all approaches in each lane for SCATS operation. The City of Marietta intersections use video detection and the City of Atlanta intersections use inductive loop detection for Project Evaluation Report 1-3 June 30, 2010

10 presence detection. Optimal presence detection for SCATS uses a 6 x15 detector in each approach lane within approximately 10 feet of the approach stop bar. In the City of Marietta and City of Atlanta, the adaptive traffic signal control system and presence detection uses existing fiber optic communications and communicates through the established traffic signal controller channels. The SCATS system software was already installed on a central server at the Cobb County TCC, which has been in use for the past few years. The City of Marietta and City of Atlanta project intersections communicate with this central server through SCATS Regional computers, allowing for cross-jurisdictional coordination of adjacent traffic signals. Regional workstations or computers have been installed at the City of Marietta TCC and at the City of Atlanta TCC for local control and the ability to make changes to their own intersections. Because this is a multi-jurisdictional project and only one SCATS server is used, all jurisdictions will be able to view all of the intersections, but they will only be able to make changes to their respective intersections Transit Signal Priority The project deployed a transit signal priority system that was compatible with the existing City of Marietta emergency vehicle pre-emption system. Only hardware/software adjustments to the existing emergency vehicle priority control equipment were necessary at the City of Marietta intersections. Additional installation of two TSP detectors and one phase selector was completed at eleven Cobb County intersections and four City of Atlanta intersections along the CCT #10 Bus Route. The detectors are only installed on approaches that the bus passes through along its route. All sixty CCT buses were outfitted with a TSP emitter. The TSP system uses existing fiber communications and communicates through the established traffic signal controller channel. The system interface software is installed on a central computer/workstation at the City of Atlanta TCC and at the Cobb County TCC, and had already been installed at the City of Marietta TCC. The City of Marietta has Opticom phase selector cards and corresponding software in all of their signal cabinets; however, they had only been using it for high priority fire trucks. Low priority pre-emption has since been enabled on those intersections, which can be achieved using the same Opticom cards and ADA Upgrades The original project scope of work included deployment of SCATS adaptive traffic signal control, TSP, and presence detection. Meanwhile, it was determined in conjunction with FHWA that ADA and intersection upgrades would be required as part of the Project. In order to perform the work associated with these additional tasks as well as the necessary intersection upgrades, GDOT let and executed another project Traffic Signal Upgrades within GRTA Smart Corridor, based on the design plans. The City of Atlanta intersections were to be upgraded as part of an on-going project. These improvements included: Replacing the existing NEMA cabinets with base mounted 336 cabinets on the existing base. Installing new 2070L controllers. Placing LED inserts in the existing signal heads. Placing LED inserts in the existing pedestrian signal heads. Because projects can be delayed for a variety of reasons, the plans developed for the Atlanta Smart Corridor Project still showed the cabinet, controller, signal, and pedestrian head replacements at select Project Evaluation Report 1-4 June 30, 2010

11 intersections. Other improvements to the City of Atlanta intersections included installing 6 x 15 inductive loops, striping, crosswalks, pedestrian signage, wheel chair ramps, concrete islands, pedestrian signals and push button stations. Four City of Atlanta intersections were also equipped with transit signal priority detectors. The Cobb County intersections did not need cabinet, controller or inductive loop replacements, however, improvements such as crosswalks, wheel chair ramps, sidewalks, cut-throughs on existing islands, pedestrian signage, pedestrian signals and push button stations were needed. All Cobb County intersections were equipped with transit signal priority detectors and many intersections needed the existing video detection cameras re-aimed on various approaches. The City of Marietta intersections mainly needed pedestrian improvements such as crosswalks, wheel chair ramps, pedestrian signage, concrete islands, pedestrian signals and push button stations. In addition, many intersections required the addition of 6 x 50 inductive loops as well as video detection cameras. Project Evaluation Report 1-5 June 30, 2010

12 2. EVALUATION PLAN The project evaluation consists of two different studies, namely Sydney Coordinated Adaptive Traffic System (SCATS) Evaluation and Transit Signal Priority (TSP) Evaluation. 2.1 Evaluation Schedule Data related to the ITS goals/objectives and measures of effectiveness was collected during two different time periods. The first data collection period was used to assess the baseline or before SCATS scenario and before TSP scenario. In this scenario, the corridor was operated according to established operating practices. The data was used to establish a baseline for the purpose of identifying the incremental change occurring in the after SCATS scenario with TSP. The before scenario is the same for both the SCATS Evaluation Plan and the TSP Evaluation Plan. A second data collection period was conducted to evaluate the after SCATS scenario. In this scenario, SCATS was activated at all intersections within the project corridor. The activated SCATS system was set based on the input parameters agreed to by GRTA and the local stakeholders. Data collection activities for the before and after scenarios were performed in both directions during three distinct peak periods until satisfactory data was collected for each of the three peak periods. Before data collection began in November The after data collection occurred after the project equipment had been implemented, tested and accepted, in June The selected data collection periods represent periods of normal traffic flow (i.e., do not include holidays, work days excluding Mondays and Fridays) agreed to by the local stakeholders. The three distinct peak periods for data collections include A.M. Peak Period: from 6:00 a.m. to 10:00 a.m. Midday Peak Period: from 10:00 a.m. to 2:00 p.m. P.M. Peak Period: from 2:00 p.m. to 6:00 p.m. These time periods correspond to the transit schedule trips (peak periods) analyzed during the TSP Evaluation Plan. 2.2 Evaluation Methodologies To support the evaluation, a test plan has been developed to guide the collection and analysis of different types of data. The test plan provides instructions for conducting a specific aspect of the study. The test plan developed for this study will address Travel Time and Delay Economic Indicators Air Quality The test plan followed established procedures for documentation of external influences and conduct of quality control and quality assurance practices. The main external influences on the system s performance were weather, changes in the transportation system (lane closures, repairs, etc.), incidents causing traffic delays (crashes, stalled vehicles, etc.), and major events. Each of these external influences were continually monitored as part of the project and were considered when possible, when scheduling the individual tests of the system. A large amount of data was collected over the course of this evaluation. The following steps were taken to ensure that the data was reliable and secure: Project Evaluation Report 2-1 June 30, 2010

13 Data collection personnel were properly trained. Data was inspected in a timely manner to insure that the data was reasonable. Data quality assurance procedures were established. 2.3 SCATS Evaluation Plan The SCATS Test Plan measured the Adaptive Signal system impact on passenger vehicles within the project corridor. For this test plan the project corridor extends from South Marietta Parkway in the City of Marietta to Howell Mill Road in the City of Atlanta along US 41/Cobb Parkway/Northside Parkway. The before and after scenarios of the test plan address passenger vehicle travel time, delay, stops, fuel consumption costs, stop comparison, and air quality by means of field travel time runs and post processing of data using PC Travel software. Of note, the portion of the project corridor from Lake Park Drive to Paces Mill Road in Cobb County is already SCATS controlled and is part of the before scenario of the test plan Travel Time and Delay Travel time and delay were recorded from a probe vehicle driven along the corridor by a member of the evaluation team. The device used to collect and analyze the travel time and delay data was a lap top computer in conjunction with a GPS Travel Time Data Collector and PC Travel software. When the data collected by the GPS data collector was analyzed using the PC Travel software, travel time, delay, and stop statistics were calculated. The floating car method was used, whereby the probe vehicle driver estimates the median speed of the traffic flow by passing and being passed by an equal number of vehicles Economic Indicators To calculate the costs incurred by the motoring public due to stopped delay, the delay benefit is estimated by multiplying the average change in delay per vehicle for a peak period (A.M., Midday, P.M.) between the before and after conditions by the two-hour traffic volume for that respective period. Because before/after data was collected during the weekday peaks only, the results can only be applied to like conditions; therefore, assuming there are 250 days per year with similar conditions, the annual delay benefit is estimated by the change in delay for the period multiplied by 250 days with a dollar value of $12 per hour and 1.2 occupants in each vehicle. This value is widely recognized in recent publications as the accepted cost of delay and includes the costs of wasted person time and vehicle operating costs. In equation form, the estimation is as follows: Annual Delay Benefit = ([A.M. Change x 2 Hr Volume] + [Mid Day Change x 2 Hr Volume] + [P.M. Change x 2 Hr Volume]) x $12/Hr x 250 Days/Year x 1.2 Occupants/Vehicle Costs due to delays (time) that result in reduced rates of travel are reflected in the above equation. Speed changes, however, result in increased vehicle operating costs, including increased fuel consumption. Each time a vehicle decelerates, idles, then accelerates back to running speed, the costs for fuel is increased compared to operation at a constant speed. To calculate the costs incurred by the motoring public due to increased stops, and thus increased fuel consumption, the fuel benefit is estimated by multiplying the average change in the number of stops per vehicle for a peak period between the before and after conditions by the two-hour traffic volume for that respective period. The annual benefit is estimated by multiplying the change in total stops for the period by 0.6 and then multiplying by the current fuel cost per gallon. This value comes from an update to the AASHTO Manual on Road User Benefit Analysis. In equation form, the estimation is as follows: Project Evaluation Report 2-2 June 30, 2010

14 Annual Fuel Benefit = ([A.M. Change x 2 Hr Volume] + [Mid Day Change x 2 Hr Volume] + [P.M. Change x 2 Hr Volume]) x 0.6 x Current Fuel Cost/Gallon Air Quality Vehicular emissions are a function of delay, which in turn affects air quality. The estimate of air quality is based strictly on changes in stopped delay. Emission benefits are calculated for the three major sources of emissions: volatile oxygen compounds (VOC), nitrous oxides (NOx), and carbon monoxide (CO). The emission benefits are determined by multiplying the annual delay benefit (hours) by the appropriate idling emission factors (g/hr). The resulting emission benefits (g) are then converted to pounds of emissions reduced. The emission factors used were obtained from MOBILE 5b (an average of winter and summer conditions), and are recognized as appropriate values. The annual delay benefit is calculated as follows: Annual Emission Benefit = ([A.M. Change x 2 Hr Volume] + [Mid Day Change x 2 Hr Volume] + [P.M. Change x 2 Hr Volume]) x 250 Days/Year x Idling Factor It is important to note that this analysis only accounts for improvement due to reduced idling during weekday peak traffic periods during which the travel studies were conducted. In reality, benefits will be realized for non-peak and weekend periods, however, due to decreased travel times and increased speeds the modeling of such efforts is not feasible within the scope of this effort. 2.4 TSP Evaluation Plan The Transit Signal Priority plan is slightly different than the SCATS evaluation plan. It is essentially a test to see how bus priority helps the public transport users and also a study of transit travel time, delay, and transit level of service. For this test plan, two people will ride the CCT Route 10 bus, which operates from Marietta to the Cumberland Boulevard Transfer Center via U.S. 41, then to the MARTA Arts Center Station (see Figure 2-1). Figure 2-1: CCT Route 10 Map (Source: Project Evaluation Report 2-3 June 30, 2010

15 The three distinct peak periods for data collection include: A.M. Peak Period: Start at 6:00 a.m. with the outbound bus at the Marietta Transfer Center and end at approximately 10:00 a.m. with the inbound bus to the Marietta Transfer Center. Midday Peak Period: Start at 10:00 a.m. with the outbound bus at the Marietta Transfer Center and end at approximately 2:00 p.m. with the inbound bus to the Marietta Transfer Center. P.M. Peak Period: Start at 4:00 p.m. with the outbound bus at the Marietta Transfer Center and end at approximately 6:00 p.m. with the inbound bus to the Marietta Transfer Center. For this evaluation, one or two people rode the CCT Route 10 bus and collected timestamp data at various bus stop locations and intersections along the project corridor. Northbound runs were conducted beginning at the bus stop after Paces Mill Road and ending at the Marietta Transfer Center. Southbound runs began at the Marietta Transfer Center and ended at the bus stop after Paces Mill Road. The before transit study consisted of four days worth of data collection in November and December of 2009, while the after study consisted of five days of data collection in mid June of Number of runs varied from six to eight per direction (northbound or southbound) each day. Travel time runs were only done on Tuesday, Wednesday or Thursday to ensure average results. It is important to note that statistically, the data sampling is very small, so the results are not as accurate as if there were several months of data collected. These results do, however, give us an idea of some general trends and allow a general comparison between the before and after conditions. Arrival and departure times were collected at the four major stops which are listed on the CCT Route 10 bus schedule including Cumberland Blvd. Transfer Center, Cobb Parkway and Clock Tower, Dobbins Air Reserve Base, and the Marietta Transfer Center. Arrival times were noted at intermediate bus stops that are not listed on the published schedule. Also, if the bus had to stop at any signalized intersections along the corridor, the number of seconds of delay was recorded. These timestamps were then input into a Microsoft Excel spreadsheet specifically designed for this project. Five performance measures were evaluated including average travel time and standard deviation of travel time, average intersection stop time and stop rate, and on-time performance level of service. The average travel time and standard deviation of travel time was determined along various segments of the project corridor. stop time and stop rate was calculated at seven major City of Marietta intersections, including Spinks Dr., Atlantic Ave./Dobbins ARB, Franklin Rd., Enterprise Way, Airport Industrial Park Dr., Terrell Mill Rd., and Windy Hill Rd. On-time performance level of service was determined at the four major CCT Route 10 bus stops with published timetables which included Cumberland Blvd. Transfer Center, Cobb Parkway and Clock Tower, Dobbins Air Reserve Base, and the Marietta Transfer Center. Project Evaluation Report 2-4 June 30, 2010

16 3. EVALUATION RESULTS 3.1 SCATS Evaluation Results The following summary shows a comparison of the before and after average travel times, number of vehicle stops, vehicle delay, vehicle emissions, and fuel consumption recorded at intersections while conducting the studies. Data are shown for each jurisdiction (City of Atlanta, Cobb County, City of Marietta), time period, and direction of travel. An annual cost and benefit/cost ratio was then calculated for this project using the results of this study Travel Time Vehicle travel times were obtained for the, which consisted of three sections: City of Atlanta Cobb County City of Marietta Average A.M., Noon, and P.M. travel times were determined by direction for each day and then across all days of the study period. The travel time summary for the before and after studies is shown in Table 3-1. From the above results, the travel time decreased after the implementation of SCATS on all sections in both directions. The southbound direction showed a greater reduction in travel time than the northbound direction. The largest overall improvement was in the A.M. peak, with a 29% reduction in travel time. The Noon and P.M. peaks saw an overall reduction of 17% and 21%, respectively. The total reduction in travel time across all peak periods was 22%. Project Evaluation Report 3-1 June 30, 2010

17 Table 3-1: Before and After Travel Time Comparison Time Direction Volume Distance Before Travel Time After Travel Time Improvement per Vehicle Period Per Vehicle Total Per Vehicle Total Time per vehicle Total Time Percentage (veh) (feet) (sec/veh) (hrs/year) (sec/veh) (hrs/year) (sec/veh) (hrs/year) City of NB 1,100 14, , , ,978 38% Atlanta SB 2,100 14, , , ,027 48% AM Cobb NB 3,400 12, , , ,262 14% Peak County SB 4,750 11, , , ,637 34% City of NB 1,675 11, , , ,201 13% Marietta SB 3,250 11, , , ,634 20% City of NB 1,950 14, , , ,075 33% Atlanta SB 2,100 14, , , ,208 25% Noon Cobb NB 4,250 12, , , ,492 3% Peak County SB 4,900 11, , , ,962 23% City of NB 3,450 11, , , ,720 15% Marietta SB 3,550 11, , , ,614 14% City of NB 2,600 14, , , ,012 33% Atlanta SB 2,000 14, , , ,968 22% PM Cobb NB 5,500 12, , , ,159 7% Peak County SB 4,750 11, , , ,874 30% City of NB 4,300 11, , , ,858 28% Marietta SB 3,300 11, , , ,023 15% Total NB AM Peak Total SB AM Peak Total AM Peak Total NB Noon Peak Total SB Noon Peak Total Noon Peak Total NB PM Peak Total SB PM Peak Total PM Peak Total of all Vehicles in all Peaks 1, , , ,441 19% 1, , , ,297 35% 2, ,731 1, , ,738 29% 1, , , ,287 12% 1, , , ,784 21% 2, ,082 1, , ,071 17% 1, , , ,028 18% 1, , , ,865 25% 2, ,340 1, , ,893 21% 7,147 1,690,153 5,447 1,319,451 1, ,702 22% Project Evaluation Report 3-2 June 30, 2010

18 3.1.2 Vehicle Delay Vehicle delay was calculated for the same three sections of the listed above. A.M., Noon, and P.M. delay values were determined by direction for each day and then across all days of the study period. The delay summary for the before and after studies is shown in Table 3-2. Table 3-2: Before and After Delay Comparison Time Direction Volume Distance Before Delay After Delay Improvement per Vehicle Period Per Vehicle Total Per Vehicle Total Time per vehicle Total Time Percentage (veh) (feet) (sec/veh) (hrs/year) (sec/veh) (hrs/year) (sec/veh) (hrs/year) City of NB 1,100 14, , , , % Atlanta SB 2,100 14, , , , % AM Cobb NB 3,400 12, , , , % Peak County SB 4,750 11, , , , % City of NB 1,675 11, , , , % Marietta SB 3,250 11, , , , % City of NB 1,950 14, , , , % Atlanta SB 2,100 14, , , , % Noon Cobb NB 4,250 12, , , , % Peak County SB 4,900 11, , , , % City of NB 3,450 11, , , , % Marietta SB 3,550 11, , , , % City of NB 2,600 14, , , , % Atlanta SB 2,000 14, , , , % PM Cobb NB 5,500 12, , , , % Peak County SB 4,750 11, , , , % City of NB 4,300 11, , , , % Marietta SB 3,300 11, , , , % Total NB AM Peak Total SB AM Peak Total AM Peak Total NB Noon Peak Total SB Noon Peak Total Noon Peak Total NB PM Peak Total SB PM Peak Total PM Peak Total of all Vehicles in all Peaks , , ,086 37% , , ,360 61% 1, , , ,446 54% , , ,059 21% , , ,277 39% 1, , , ,335 31% , , ,702 32% , , ,870 44% 1, , , ,572 37% 3, ,624 2, ,271 1, ,353 40% From the above results, vehicle delay decreased after the implementation of SCATS on all sections in both directions. Similar to the travel time, the southbound direction showed a greater reduction in vehicle delay than the northbound direction. The largest overall improvement was in the A.M. peak, with a 54% Project Evaluation Report 3-3 June 30, 2010

19 reduction in vehicle delay. The Noon and P.M. peaks saw an overall reduction of 31% and 37%, respectively. The total reduction in vehicle delay across all peak periods was 40% Vehicle Stops Vehicle stops were calculated for the same three sections of the listed above. A.M., Noon, and P.M. delay values were determined by direction for each day and then across all days of the study period. The vehicle stops summary for the before and after studies is shown in Table 3-3. Table 3-3: Before and After Vehicle Stops Comparison Time Direction Volume Distance Before Stops After Stops Improvement per Vehicle Period Per Vehicle Total Per Vehicle Total Stops per vehicle Total Stops Percentage (veh) (feet) (stops/veh) (stops/year) (stops/veh) (stops/year) (stops/veh) (stops/year) City of NB 1,100 14, , , , % Atlanta SB 2,100 14, ,730, ,050, ,680, % AM Cobb NB 3,400 12, ,400, ,975, , % Peak County SB 4,750 11, ,135, ,156, ,979, % City of NB 1,675 11, , , , % Marietta SB 3,250 11, ,354, , , % City of NB 1,950 14, ,044, , , % Atlanta SB 2,100 14, ,025, , ,275, % Noon Cobb NB 4,250 12, ,260, ,427, ,833, % Peak County SB 4,900 11, ,575, ,287, ,287, % City of NB 3,450 11, ,581, ,443, , % Marietta SB 3,550 11, ,535, ,294, ,241, % City of NB 2,600 14, ,841, , ,470, % Atlanta SB 2,000 14, ,666, , , % PM Cobb NB 5,500 12, ,555, ,020, , % Peak County SB 4,750 11, ,125, ,750, ,375, % City of NB 4,300 11, ,479, ,090, ,388, % Marietta SB 3,300 11, ,375, , , % Total NB AM Peak Total SB AM Peak Total AM Peak Total NB Noon Peak Total SB Noon Peak Total Noon Peak Total NB PM Peak Total SB PM Peak Total PM Peak Total of all Vehicles in all Peaks 9.2 5,102, ,153, ,583 19% ,219, ,134, ,084,762 40% ,322, ,287, ,034,346 33% ,886, ,114, ,771,726 28% ,135, ,331, ,803,944 52% ,022, ,446, ,575,669 42% ,876, ,482, ,393,501 23% ,166, ,569, ,597,024 35% ,043, ,052, ,990,525 28% ,387, ,786, ,600,540 34% From the above results, vehicle stops decreased after the implementation of SCATS on all sections in both directions, except for the northbound noon peak in the City of Marietta. The after study showed an increase of one stop along the 2.25 mile section, which consists of seven intersections. With a relatively small number of travel time runs, the average number of stops could have been skewed by a run that was Project Evaluation Report 3-4 June 30, 2010

20 during either an incident or special event. Since the overall number of stops was low on this section, a one stop increase increased the vehicle stop percentage dramatically. As with travel time and delay, the southbound direction showed a greater reduction in vehicle stops than the northbound direction. The largest overall improvement was in the Noon peak, with a 42% reduction in vehicle stops. The A.M. and P.M. peaks saw an overall reduction of 33% and 28%, respectively. The total reduction in vehicle stops across all peak periods was 34% Environmental Pollution Emissions Atmospheric pollutants are emitted from vehicles when they are stopped or idling. Carbon monoxide, oxides of nitrogen, and volatile oxygen compounds (hydrocarbons) are three types of vehicle emissions that are regulated by federal law. New signal timing can reduce these pollutants by reducing the number of stops vehicles make and having vehicles travel at a constant speed. Table 3-4 through Table 3-6 show a comparison of the before and after emissions for both directions of this project for CO (carbon monoxide), NOx (oxides of carbon), and VOC (volatile oxygen) emissions. Negative values in the tables indicate an increase in emissions rather than a decrease. Table 3-4: Comparison of CO Emissions CO Time Direction Volume Before After Improvement per Vehicle Period Per Veh Per Hour Total Per Veh Per Hour Total Per Veh Total Percentage (g) (kg) (g) (g) (kg) (g) (g) (g) Total NB AM Peak ,214, ,384, ,170, % Total SB AM Peak Total AM Peak Total NB Noon Peak Total SB Noon Peak Total Noon Peak Total NB PM Peak Total SB PM Peak Total PM Peak Total of all Vehicles in all Peaks ,807, ,095, ,712, % ,022, ,479, ,457, % ,800, ,594, ,794, % ,670, ,102, ,432, % ,471, ,697, ,226, % ,951, ,628, ,676, % ,800, ,769, ,969, % ,751, ,397, ,646, % ,241,244, ,403,574, ,330, % Table 3-5: Comparison of NOx Emissions NOX Time Direction Volume Before After Improvement per Vehicle Period Per Veh Per Hour Total Per Veh Per Hour Total Per Veh Total Percentage (g) (kg) (g) (g) (kg) (g) (g) (g) Total NB AM Peak ,508, ,772, , % Total SB AM Peak Total AM Peak Total NB Noon Peak Total SB Noon Peak Total Noon Peak Total NB PM Peak Total SB PM Peak Total PM Peak Total of all Vehicles in all Peaks ,278, ,629, ,649, % ,786, ,402, ,384, % ,228, ,061, , % ,825, ,749, ,075, % ,054, ,811, ,242, % ,097, ,717, ,619, % ,128, ,976, ,848, % ,225, ,693, ,467, % ,066, ,906, ,840, % Project Evaluation Report 3-5 June 30, 2010

21 Table 3-6: Comparison of VOC Emissions VOC Time Direction Volume Before After Improvement per Vehicle Period Per Veh Per Hour Total Per Veh Per Hour Total Per Veh Total Percentage (g) (kg) (g) (g) (kg) (g) (g) (g) Total NB AM Peak ,432, ,413, ,019, % Total SB AM Peak Total AM Peak Total NB Noon Peak Total SB Noon Peak Total Noon Peak Total NB PM Peak Total SB PM Peak Total PM Peak Total of all Vehicles in all Peaks ,735, ,944, ,791, % ,168, ,357, ,810, % ,732, ,368, , % ,812, ,244, ,568, % ,544, ,613, ,931, % ,787, ,672, , % ,350, ,467, , % ,138, ,140, , % ,851, ,110, ,740, % From the above tables, there was an overall increase in carbon monoxide emissions of 5.9%, a decrease in oxides of carbon of 1% and a decrease in volatile oxygen of 8.5%. The increase in carbon monoxide emissions is due to the reduced travel times, and hence increased speeds, along the project corridor Project Benefits There are financial costs associated with the development and implementation of improved signal timing plans. However, there are also financial benefits that are derived from the improvements in traffic flow experienced by drivers using the roadways. Drivers will continue to benefit from improvements in traffic flow over the lifetime of the timing plans. The reductions in delay and travel time documented previously are of much greater value than simply reducing driver frustration and inconvenience. Rather, time spent by people in traffic congestion is time that cannot be used for revenue producing activities. The time saved by drivers due to improved signal timing has a dollar value that can be calculated with the following formulas: Annual Delay Benefit = ([A.M. Change x 2 Hr Volume] + [Mid Day Change x 2 Hr Volume] + [P.M. Change x 2 Hr Volume]) x $12/Hr x 250 Days/Year x 1.2 Occupants/Vehicle Annual Fuel Benefit = ([A.M. Change x 2 Hr Volume] + [Mid Day Change x 2 Hr Volume] + [P.M. Change x 2 Hr Volume]) x 0.6 x Current Fuel Cost/Gallon For the purpose of this study, the cost of delay was assumed to be $12.00 per person/hour. Average vehicle occupancy was assumed to be 1.2. Fuel was assumed to cost $2.70 per gallon. The timing was assumed to be in effect 250 days per year. Table 3-7 shows the comparison of fuel consumption and Table 3-8 shows the dollar value of reduced travel time and reduced fuel consumption for the Atlanta Smart Corridor during the A.M. peak, Noon, and P.M. peak periods. Project Evaluation Report 3-6 June 30, 2010