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Suggested Citation:"Chapter 1 - Introduction." National Academies of Sciences, Engineering, and Medicine. 2007. Design, Operation, and Safety of At-Grade Crossings of Exclusive Busways. Washington, DC: The National Academies Press. doi: 10.17226/23171.
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Suggested Citation:"Chapter 1 - Introduction." National Academies of Sciences, Engineering, and Medicine. 2007. Design, Operation, and Safety of At-Grade Crossings of Exclusive Busways. Washington, DC: The National Academies Press. doi: 10.17226/23171.
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1This report provides design and operation guidelines for at-grade crossings of exclusive busways. In support of these guidelines, this report also provides general principles of safety, design, and operation of busways and information on design controls. The guidelines are based on a detailed litera- ture review, interviews with selected transit agencies, and site visits to Cleveland, Los Angeles, Miami, Orlando, and Rich- mond (British Columbia). As such, these guidelines are, in part, a reflection of where we are today with exclusive busway at-grade intersections. The guidelines may need to be modi- fied as more at-grade crossings of exclusive busways are con- structed or as advances are made in traffic control devices, buses, and facilities. The guidelines are intended to assist transit, traffic engi- neering, and highway design agencies in planning, designing, and operating various kinds of busways through street and roadway intersections. Background Grade-separated busways have operated in Ottawa and Pittsburgh for more than 30 years. More recently, at-grade busways have been placed in service in several cities including Los Angeles, Miami, Orlando, and Richmond, and a busway is being built in the median of Euclid Avenue in Cleveland. Additional at-grade busways are likely to be built as part of ongoing bus rapid transit (BRT) initiatives. BRT systems are defined by a set of attributes that improve service speed, identity, and reliability and that are viewed by the public as superior to regular bus service. These features include • An exclusive, reserved, or priority running way that is gen- erally free from traffic congestion and delay and that pro- vides a sense of performance; • Fewer stops; • Reduced dwell times at stops; • Improved travel times and schedule reliability; • Increased comfort and aesthetically pleasing vehicles; • An understandable route structure; and • More and better information provided to existing and potential riders. Higher speeds and greater service reliability can be achieved where buses are operated in dedicated lanes or ded- icated facilities (busways). When stations, rather than bus stops are developed; when fares are collected prior to board- ing the vehicles; when the routes are simple; and when real- time operating information is available to the public, BRT systems can be viewed as similar to rail systems but with the flexibility of a bus and significantly lower development costs. Exclusive busways that are located in separate rights-of- way or within the medians of wide streets usually have grade crossings at intersecting roadways and/or pedestrian and bicycle facilities. These grade crossings have the same func- tion requirements as traditional intersections. They must accommodate the movements of conflicting streams of traf- fic, pedestrian and vehicle, conveniently and safely. The chal- lenge is to manage and accommodate the movement safely while maintaining efficient intersection operations. The movements of conflicting traffic streams must be separated in time and space. Needs of bus passengers, pedestrians, and other users of the intersection should be considered. Because there are few exclusive busways in the North American envi- ronment, confusion and a lack of respect by motorists on intersecting streets may result. Moreover, bus volumes are usually low when compared to general traffic; motorists or pedestrians traveling across the busway may be lulled into a false sense of security. Ideally, buses operating on busways should have preference over conflicting traffic (because they move more people), similar to the preference given to light rail transit. It is not clear, however, that motorists, bicyclists, and pedestrians on crossing roadways perceive busways in the same manner that C H A P T E R 1 Introduction

they perceive a light rail service, which typically has prefer- ence over general purpose traffic. There is no generally accepted set of guidelines and proce- dures to increase safety at busway intersections while permit- ting relatively high-speed operations. Therefore, agencies have had to develop their own criteria to implement busways. Objective of Study The research objective was to develop guidance that can be used by transit and highway agencies in the operations, plan- ning, and functional designs of at-grade crossings of busways in physically separated rights-of-way by roadways, bike paths, or pedestrian facilities. The resulting guidance should provide information that can be applied to enhance safety at busway crossings while maintaining efficient transit and highway operations and minimizing pedestrian delay. Scope of Study A broad range of exclusive busways are located in separated rights-of-way. Busways can provide the fastest, most reliable operation if all intersections with roadways or pedestrian and bicycle facilities are grade separated. However, exclusive busways also exist with at-grade crossings for all intersecting roadway or pedestrian and bicycle facilities, and busways exist with varied crossings (i.e., some at-grade and some grade- separated crossings). Many factors, such as traffic volumes, bus service frequency, environmental issues, costs, and access, affect the decision to have an at-grade crossing, as opposed to a grade-separated crossing. The scope of this report is guidance once the decision has been made to provide an at-grade cross- ing of an exclusive busway in a physically separated right-of- way. The guidance is a reflection of current practices and facilities of the transit systems included in this research project. This report assumes that all pertinent factors have been considered and that an engineering study has determined that an at-grade crossing is the appropriate design for the inter- section. Grade-separated crossings are outside of the scope of this report. This report includes guidance for at-grade intersections along (1) busways within street medians; (2) physically sepa- rated, side-aligned busways; (3) busways on separated rights- of-way; and (4) bus-only ramps. They include highway intersections, midblock pedestrian crossings, and bicycle crossings. Organization of Report This report is organized into eight chapters with support- ing appendixes. Chapter 2 describes the four types of inter- sections addressed in the report. Chapter 3 identifies some general principles of safety and design that should be consid- ered. Chapter 4 provides design controls and guidelines for the intersection geometry. Chapters 5 and 6 address traffic control devices and operational practices. Chapter 7 presents designs for each of the four intersection types. Chapter 8, the final chapter, discusses other considerations including enforcement, education, bus operating procedures, and con- siderations for busways in the Manual on Uniform Traffic Control Devices. The report is supported by a number of appendixes. Appendixes A and B provide interim products of the research, a literature review and a synthesis of practice. Appendixes C through G provide the results of the case studies. Appendix H describes a functional analysis that supports Chapter 3, and Appendix I provides some supporting information for Chapter 4. These appendixes have been published as TCRP Web-Only Document 36, available on the TRB website (http://www.trb.org/news/blurb_detail.asp?id=7720). 2

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TRB’s Transit Cooperative Research Program (TCRP) Report 117: Design, Operation, and Safety of At-Grade Crossings of Exclusive Busways explores planning, designing, and operating various kinds of busways through roadway intersections. The report examines at-grade intersections along busways within arterial street medians; physically separated, side-aligned busways; busways on separate rights-of-way; and bus-only ramps. The intersections highlighted include highway intersections, midblock pedestrian crossings, and bicycle crossings. Appendixes A through I of the contractor’s final report were published as TCRP Web-Only Document 36.

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