Application of IVI Technologies for Bus Rapid Transit Systems

Transcription

1 Application of IVI Technologies for Bus Rapid Transit Systems Authors: Matthew Hardy Lead Transportation Engineer Mitretek Systems 600 Maryland Ave., SW Suite 755 Washington, DC (202) and Brian Cronin General Engineer Federal Transit Administration (202) Summary: BRT systems are gaining popularity in the United States. Many of the new BRT systems will operate in unique environments (narrow lanes, shoulders, HOV lanes) where there is a sincere concern regarding the safety implications of operating such a system. This paper explores the application of Intelligent Vehicle Initiative (IVI) technologies to U.S. Bus Rapid Transit (BRT) systems that will help mitigate the safety concerns associated with BRT operations.

2 INTRODUCTION Bus Rapid Transit (BRT) refers to a flexible form of rapid transit that combines advanced bus technologies with innovative bus operations and management techniques into an integrated system to provide enhanced transportation services that approach the capabilities of light rail rapid transit systems.(1) BRT systems are designed to increase the level and quality of bus service through the integration of vehicles, facilities, services and Intelligent Transportation Systems (ITS).(2) BRT operations are not without a number of safety concerns. First, BRT vehicles will be operating at higher speeds than the buses that are larger than normally seen on roadways. BRT vehicles may also operate in environments, such as roadway shoulders and High Occupancy Vehicle (HOV) lanes, where the differential in operating speeds may pose a safety concern for public officials, state engineers and the motoring public. Second, BRT vehicles will be expected to handle a larger quantity of passengers where the safety of those passengers making their way to the BRT vehicle will be a concern. Many BRT stations will be an open environment with raised platforms and the potential for BRT vehicles to either strike passengers or collide with the station's raised platforms is a concern. Finally BRT vehicles operating in city centers on dedicated lanes will have an increased risk of striking pedestrians, vehicles illegally using the bus-only lanes, passengers concentrated around BRT stations, and vehicles at intersections equipped with bus signal priority. This paper explores the application of Intelligent Vehicle Initiative (IVI) technologies to BRT systems that will help mitigate the safety concerns associated with BRT operations. First, the paper provides an overview of BRT systems and a description of several US BRT systems. Second, this paper explores areas of opportunities for the development of IVI applications to support BRT. Third, an assessment of the likelihood of BRT systems implementing IVI applications is presented. Finally, some conclusions are made regarding the integration of IVI technologies to insure the safety of BRT systems. BRT SYSTEM OVERVIEW The goals for a BRT system are based on the goals of other rapid transit systems. A key word is rapid ; the service must be geared to providing reduced travel times to riders compared to today s bus systems.(3) There are a few forward-looking BRT systems, both in the United States. and abroad, that have combined modern bus technology with modern land use planning and transportation policies to support new concepts for rapid transit systems based on bus-like vehicles. The success of some of these pioneering systems, such as the system in Curitiba, Brazil, have shown that BRT systems are capable of providing heavily-used, high capacity rapid transit at a reduced cost.(4) With this in mind, the BRT Demonstration Program was established by FTA and funded by Congress in the Transportation Efficiency Act for the 21 st Century. Through a competitive process, seventeen sites were selected to participate in the FTA BRT Demonstration Program.(5) Five of the BRT Demonstration Program cities BRT operations are described next. This selection provides a cross-section of the variety of BRT systems that are planned or currently operating. Each section provides an overview of the roadway operational characteristics of the system and 1

3 the need for technologies to either ensure the safety of pedestrians and passengers or increase the safety of the BRT vehicle as it is in operation. CLEVELAND, OHIO The Cleveland BRT system will operate along a 10-mile corridor on Euclid Avenue, which is in the city center of Cleveland. Cleveland's BRT system will incorporate a combination of centerdedicated lanes for the western two-thirds of the route and side-dedicated lanes for the eastern one-third. Raised center platform stations as well as curb-side stops will be used throughout the system. Currently, the Cleveland system will utilize 60-foot articulated BRT vehicles. These criteria will require a unique BRT vehicle that will have doors on both sides and can safely operate at higher speeds in the city center while still being able to maneuver through some of the more narrow streets.(6) The need for technologies to ensure the safety of pedestrians, passengers, and the vehicle is of a high concern to Cleveland. First, in a number of locations along the corridor, the dedicated BRT lanes will be significantly narrowed due to bridge columns in medians and limited right-of-way. Second, at BRT stations, drivers must negotiate the BRT vehicle to a safe distance from the elevated platforms or curb so that passengers can easily and safely embark and dis-embark. With the center-platform stations, drivers must be aware of pedestrians and passengers walking through the BRT lane to either side of the street as they make their way to and from the BRT station. DULLES CORRIDOR, VIRGINIA The Dulles Corridor BRT system operates along the Dulles Toll Road in three different environments: improved shoulders, HOV lanes and dedicated BRT lanes. Once the entire BRT system is complete, elevated center stations will be in the median of the dedicated BRT lanes. Currently, the system is operating on HOV lanes and improved roadway shoulders. Operating speeds along the HOV portion are a maximum of 55 mph while the improved roadway shoulder has a maximum speed of 25 mph.(7) Dulles Corridor's BRT system will operate similar to a light-rail system. In fact, if future demand is as projected, the system will be turned into a rail system by BRT vehicles will be operating at significantly higher speeds along the corridor. Safety concerns have arisen regarding the increased speed on the improved shoulders where speed differentials will be increased and the remainder of the lane widths have been narrowed. Also, buses will need to perform a crossover before and after the stations so that passengers will be able to board the bus through standard doors on the right-side. There is currently a safety concern regarding high frequencies of BRT vehicles negotiating narrow station lanes to stop at an adequate and safe distance from the elevated platform. EUGENE, OREGON Eugene Oregon's BRT system will consist of a dedicated busway between two city center areas. There are several situations within the Eugene system where safety will become an issue. First, there are several areas along the busway where the ROW is either significantly narrowed or BRT vehicles will have to share a lane creating safety concerns with vehicle collisions. Second, when the BRT vehicles are operating in city centers, there is concern about the safety of pedestrians 2

4 and patrons at BRT stations. Finally, the design of the busway is rather narrow with very small tolerances for operation of the bus. Already Eugene is investigating the use of technology to assist drivers of the BRT vehicles so that they can be operated safely at higher speeds.(8) HARTFORD, CONNECTICUT The Hartford BRT system will use a dedicated busway constructed adjacent to existing AMTRAK right-of-way in a suburban corridor. There are currently some technical issues with barrier protection between the vehicles operating on the busway and the AMTRAK trains. The system will include stations that are longitudinally offset from one another and also include an extra center lane so that vehicles will be able to by-pass stations if needed without having to wait for buses at each station. There are currently three intersections that may need to have a gradeseparated interchange or some type of intersection control technology. LOS ANGELES, CALIFORNIA Los Angeles' Metro Rapid BRT service operates along two urban corridors: Ventura Boulevard corridor and the Whittier-Wilshire Boulevards corridor. The Metro Rapid service is an allexpress bus service with stops every 0.7 or 0.8 miles. The heart of the Metro Rapid system is the signal priority loop detection technology that is installed along the corridor and is tied into the local traffic signal controllers. Transponders on the BRT vehicles identify each vehicle as they pass over the loop detectors. Data from the BRT vehicle is then transmitted to a control center that is able to provide some level of control and observation of the BRT fleet. Because of the operating characteristics of Metro Rapid, there has been some concern regarding the safety of passengers at stops and pedestrians at the intersections where BRT vehicles receive priority. Concern has also been expressed regarding vehicle collisions at intersections and stations as well. Phase I of the Metro Rapid system is operational and has seen great success. Average speeds have increased 29% on the Wilshire-Whittier corridor and 23% along the Ventura corridor.(9) However, high ridership has resulted in extended dwell times. Higher capacity buses and multiple boarding doors will be implemented as part of Phase II. IVI APPLICATIONS FOR BRT The Intelligent Vehicle Initiative (IVI) is a segment of a larger U.S. DOT ITS initiative and underscores the significant and continuing role of the driver in achieving improved highway safety. The U.S. DOT s vision for IVI is a system of roads, vehicles, and drivers, where Americans:(10) Operate in a significantly safer environment Enjoy greater mobility and efficiency as a result of the widespread use of vehicle-based autonomous and infrastructure-cooperative driving assistance features The activities conducted under the IVI program emphasize problem areas such as rear-end collisions, roadway departure collisions, lane change and merge collisions, and intersection collisions. Potential countermeasures for these problem areas include vehicle-based and vehicleinfrastructure cooperative communication systems. Research is being conducted to develop 3

5 performance guidelines, specifications, objective test procedures, architectures, and standards, and will test and evaluate the safety impact of the most promising configurations. Three IVI technologies have been identified that are specific to BRT applications and meet the IVI vision: Lane Assist, Precision Docking and Intersection Warning. Most of these technologies will serve a dual purpose of both ensuring safety and improving operational efficiencies to meet the goals of the BRT system. LANE ASSIST The premise behind lane assist technology is to increase the safety of BRT vehicles as they operate in the more unique environments, such as narrow lanes. Lane assist technology will allow BRT vehicles to operate at the desired higher operating speeds while maintaining the safety of the passengers, BRT vehicles and the motoring public. Lane assist technology can significantly help BRT vehicles operating in the following environments: Narrow Lanes Where ROW restrictions are severely limited and lateral movement tolerances are low. HOV Lanes In situations where there is no positive separation of HOV lanes from non- HOV lanes, speed differentials may limit the maximum speed of buses. Bus Shoulder Lanes Bus shoulder lanes are usually some type of improved lane where buses may operate either at certain times or only when there is congestion. This presents a safety issue of increased speed differentials and the increased probability of BRT vehicles colliding with violators who use the bus shoulder lane to bypass the congestion. In addition to maintaining safety, lane assist technology will also allow BRT vehicles operating on dedicated lanes in their dedicated ROW the ability to provide a rail-like image, which is a highly desirable feature of most BRT systems. PRECISION DOCKING Precision docking technologies will serve two primary purposes for BRT safety of the passengers and vehicle and reduced station dwell time. The primary purpose will be to ensure the safety of passengers, pedestrians and the vehicle. Since the BRT vehicles will be operating at higher speeds and many stations will be elevated with loading from both sides, drivers will have an increased risk of hitting passengers or colliding with platforms or curbs. Precision docking will ensure that BRT vehicles consistently stop at the correct location at the station, both longitudinally and latitudinally, and therefore increase passenger confidence as well as driver confidence. The secondary purpose of precision docking technologies will be reduced station dwell times. Since the BRT vehicle will be stopping at the same point each time, passenger queue locations can be marked on station platforms to reduce boarding and dwell times. INTERSECTION WARNING Intersection warning technologies will give BRT vehicle drivers operating in an urban environment greater confidence as they travel through congested corridors and are given signal priority at signalized intersections. BRT vehicles will be carrying a higher capacity of passengers 4

6 and operating at higher speeds where accidents are a serious concern. Drivers will have to be more aware of their surroundings while at the same time ensuring that passenger safety. Station location along with signal priority presents an increased risk of hitting passengers entering and exiting the vehicle as well as pedestrians in crosswalks. All of these conditions provide the potential for serious accidents between BRT vehicles and pedestrians. Warning and avoidance systems either at key intersections or BRT stations will help to ensure the safety of pedestrians and passengers alike. BRT AND IVI ASSESSMENT Table 1 provides an analysis of the likelihood that an IVI application would be implemented in the six transit systems that are described in Section 0. Each of the BRT systems was summarized within three individual categories: Roadway Operations Characteristics (Dedicated Lanes, Semi- Dedicated Lanes, Mixed Traffic Expressway Operations, Mixed Traffic Corridor & Street Operations); BRT System Type (Express Service, Urban Shuttle, or Local Service); and BRT Station Characteristic (Level Boarding or ease of Access).(3) In addition, the BRT system was classified as either operating in a City Center, Suburban Corridor or Urban Corridor. The likelihood of implementing each of the IVI Applications for BRT was indicated as either Very Likely, Likely or Unlikely. An overall rating, summarizing the three individual categories is provided as well. 5

7 Table 1 IVI Applications to Select FTA BRT Demonstration Sites IVI Applications for BRT Lane Assist Precision Docking Intersection Warning Cleveland, OH City Center Semi-Dedicated Lanes Urban Shuttle Level Boarding at Stations Dulles Corridor, VA Subruban Corridor Mixed Traffic Expressway Operations Express Service Level Boarding at Stations Eugene, OR City Center Dedicated Lanes Express Service Level Boarding at Stations Hartford, CT Suburban Corridor Dedicated Lanes Local Service Ease of Access for Passengers Los Angeles, CA Urban Corridor Mixed Corridor & Street Operations Express Service Ease of Access for Passengers Very Likely, Likely, Unlikely Source: Author's Assessment 6

8 CONCLUSIONS BRT systems are gaining popularity in the United States. It is expected that BRT systems will become more of the "norm" rather than the exception in the next decade. Since BRT is currently seen as an alternative to rail systems, BRT's success will depend on a system operating at or near the capacity of rail systems and possessing similar characteristics. In order for BRT systems to be successful and achieve their desired system goals (reduced travel time, reduced dwell time, improved service, rail-like image), the BRT vehicles will have to operate at higher speeds. However, there is a sincere concern regarding the safety implications of operating such a system. In many cases the operating environments of the BRT vehicles will not be conducive to higher operating speeds. One way to mitigate these safety concerns is through the use of IVI technologies that will ensure the safety of the pedestrians and passengers but, the BRT vehicle as well. As presented in this paper and summarized in Table 1, there are a number of opportunities to implement IVI technologies in order for the goals of the BRT system to be met while still maintaining the safety of the system. To meet that end, the Federal Transit Administration (FTA) has partnered with Metro Transit in Minneapolis, Minnesota and the University of Minnesota to develop national requirements for lane assist and guidance systems to be used for BRT applications. The project was completed in February The major conclusions of the project are as follows: (11) 1. National operational and environmental requirements are so broad that a single technology or system available today is unable to meet the core set of national requirements. 2. Lane assist and precision docking systems are still in the early stages of system development. Insufficient operational experience disallows any statistically valid claim to system performance, system reliability, maintenance requirements, failure modes, etc. Too few of these systems have been deployed worldwide. Systems, which have been deployed, have suffered from a lack of development and testing. This premature deployment has reduced public and driver acceptance of these systems. 3. No single technology exists which will meet a reasonable subset of the requirements provided by US transit properties. If lane assist and precision docking systems are to be deployed in the US, these systems (in the near term) will require an integration of the emerging technologies. 4. In the near term, individual transit agency requirements will dictate which mix of technologies will be used for lane assist and precision docking systems. Each transit agency will be required to perform a benefits/cost analysis to determine both the technologies to be utilized and the role each will play in their BRT system. Based upon these conclusions, and other industry recommendations, the FTA will be developing a comprehensive research program to help address many of the concerns currently facing the industry. Already there are some cities moving out with the deployment of these technologies. For example, Las Vegas, Nevada will deploying a precision docking system in Fall 2003; the 7

9 first such operational system in the United States. And, Eugene, Oregon is still pursuing the deployment of a lane assist and precision docking technologies for their BRT system. Many of these early adopters will provide valuable experience in the deployment and operation of the IVI technologies for BRT 8

10 BIBLIOGRAPHY (1) General Accounting Office. Bus Rapid Transit Shows Promise. Washington, D.C.: GAO Report #GAO September (2) Why More Communities are Choosing Bus Rapid Transit. Washington, D.C.: National Research Council, Transportation Research Board (3) Federal Transit Administration, Bus Rapid Transit Vehicle Characteristics. Washington, D.C.: U.S. DOT #FTA-DC , June (4) Thomas, Edward. "Introduction to Vehicle Design and Deployment Strategy," presentation at BRT Vehicle Design Meeting. Washington, D.C.: Federal Transit Administration, February 9, (5) FTA Bus Rapid Transit Web Site < (November 3, 2001). (6) Mitretek Systems. Analysis of Available BRT Vehicle Options to Support the Greater Cleveland Regional Transit Authority. Prepared for the Federal Transit Administration. Washington, D.C.: July 10, (7) Personal site visit to Dulles Toll Road (July 2001). (8) Carey, Graham. "Arterial Bus Operations: Median Bus Lanes in Eugene, Oregon," paper presented at Bus Rapid Transit Demonstration Program: Workshop on Transit Operations, Traffic Engineering and Infrastructure. Miami, Florida: Federal Transit Administration, May 15-16, (9) Okazaki, James. Transit Priority System Preliminary Evaluation Report. Los Angeles, California: L.A. DOT, September 29, (10) Joint Program Office. Intelligent Vehicle Initiative Business Plan. Washington, D.C.: U.S. DOT, July (11) Federal Transit Administration, Bus Rapid Transit Lane Assist Technology Systems: Volume 1 Technology Assessment. Washington, D.C.: U.S. DOT # FTA-MN , February