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40 Bus use of shoulder operations have been working success- fully for more than a decade in several locations. They have been implemented in a variety of forms for a variety of pur- poses, but they appear to have a number of common traits. Bus bypass shoulder (BBS) applications minimize congestion- related schedule reliability problems, improve the competi- tive travel times for buses versus cars, are low cost and easy to implement, do not require new rights-of-way, and are not visually obtrusive. The early BBS projects appear to have been implemented without rigorous analysis and their success is reflected in the absence of post-project evaluation reviews and also by the expanding list of BBS projects. If accidents had proven to be a problem, safety evaluations would likely have been conducted and some BBS projects might have been abandoned. The few very short segments of BBS that have been abandoned are understood to have been upgraded to full bus lane operations. Indeed, the BBS practice is expanding, particularly in communities that have established BBS expe- rience. Georgia has recently joined the list of states with BBS operations, California has implemented a pilot project, and Florida is scheduled to begin limited BBS operations. BBSâs context-sensitive design features (low visual impact), low cost, ease of implementation, and support of more efficient and attractive transit services are features that resonate with numerous public policies. The BBS concept also appears to be popular with bus pas- sengers, who enjoy the feeling of preference as their bus moves past stop-and-go traffic in the general purpose traffic lanes. It is not uncommon for passengers to suggest to bus drivers that they move onto the shoulder when traffic begins to slow. Their perceived travel time benefits are generally greater than actual, but because perception is a key factor in affecting travel choices and increasing transit market share it is very important. Although the bus use of shoulders is not an ideal highway/ traffic operations concept, its 10-year-plus operations history in the Minneapolis metropolitan area indicates that it can be implemented relatively effectively and safely. The Twin Cities BBS application is a very low-cost effort with respect to pavement markings and signage, yet this low level signage and markings operation has proven to be safe. Actual data on operations and patronage benefits is sketchy for established BBS operations, as are the processes used to implement the shoulder use projects. Newer BBS project implementations are tending to be more rigorous and to provide a detailed record of the policy and analytical processes. Implementation of these new projects will prove useful at providing a more quantitative understanding of BBS. A cooperative or partnership approach involving transit operations, departments of transportation, police, and metro- politan planning organizations appears to be crucial in plan- ning, implementing, and operating BBS projects. Of the study objectives of this synthesis report, data on many of the issues were either not readily available or not available at all. Better information would be useful to com- munities considering implementation of BBS and those interested in improving current BBS projects. It might also be valuable for âNew Startsâ project alternative definitions and evaluations. Information on early BBS projects is primarily limited to what can be observed on the highways. Little history exists on the institutional, legal project development process, costs, and performance of these early BBS projects. This important information is becoming available for the more recent and the planned projects (i.e., Georgia 400, planned MiamiâDade BBS, and San Diego BBS). What is clear is that the an increasing number of commu- nities are pursuing shoulder use projects and that an imple- mentation checklist and a TCRP document similar to that prepared for TCRP Report 90: Bus Rapid Transit, might be useful. Key issues warranting further research are: ⢠What are the market and patronage benefits associated with BBS and how can project design maximize these benefits? Surveys might be useful to better understand passenger perceptions as well as the perceptions of motorists using the adjacent general purpose lanes. Understanding the perceptions of these groups might help to design better BBS projects as well as provide guidance to marketing efforts. Quantification of before and after patronage in corridors is also needed. ⢠What are the bus running time and reliability benefits resulting from BBS operations? Tracking bus service performance using global positioning systems could help to quantify operational benefits. A survey of bus drivers could complement the global positioning sys- tem monitoring program and provide added insights CHAPTER FOUR CONCLUSIONS AND FURTHER RESEARCH
41 into program benefits and opportunities to enhance the BBS concept. ⢠What is the safety history of BBS operations and how might the design of BBS applications minimize safety risks? From a review of accident data and discussions with enforcement and driver training and bus safety staff, key safety concerns and myths might be described. ⢠Most of the BBS projects that have been implemented employed a multi-agency team planning, design, and im- plementation approach. More information is required on these multi-agency partnership efforts, as well as legal aspects of project implementation. ⢠What geometric improvements are needed and what are their guidelines for costs? The minimum widths need further definition. Should shoulders be wider on bridges and underpasses and other segments with horizontal ob- structions nearby? Is there a maximum distance that min- imum width shoulders are tolerable? Should shoulders be wider at sharp curves? What are desired geometrics for BBS transitions and interchange ramp weave areas? What is the minimum pavement strength required? How important are modifications to drainage inlets? What are the desired and maximum drainage cross slopes for BBS shoulders? What lighting improvements, if any, are desired for the BBS segments? What minimums can be accepted, particularly for interim applications? ⢠What signage and striping guidelines and standards are recommended and could these be included in the next update of the Manual on Uniform and Traffic Control Devices? ⢠How might variable or changeable message signs and ITS technologies be used to improve BBS safety? ⢠What speeds are safe for BBS operations and how do bus volumes and shoulder width dimensions influence safe speeds? ⢠What are the advantages and disadvantages of speed- limited BBS operations versus Ottawaâs higher speed operations?
