Bicycle Railing Height Report - AASHTO - Subcommittee on Design

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DETERMINATION OF APPROPRIATE RAILING HEIGHTS FOR BICYCLISTS NCHRP 20-7 (168) Results of the Literature Review Literature relevant to appropriate railing heights for bicyclists is limited. As such, research and communication with committee members involved in the adoption of <strong>AASHTO</strong> bicycle railing height guidelines was performed. This effort determined that no scientific analysis was conducted to warrant the degree of safety of a 1.1-meter (42- inch) versus a 1.4-meter (54-inch) railing height. The lack of available <strong>AASHTO</strong> Committee meeting minutes and documentation outlining the adoption process creates a challenge for researchers. Due to the lack of empirical data, supplemental resources were consulted to aid in the determination of an appropriate railing height for bicyclists. The supplemental resources included documents on bridge design aesthetics, dimensions of the human body, center of gravity issues, and bicycle crash data. Several resources discuss the effects of inappropriately introducing a man-made object, such as a railing, into the foreground of a scenic view. Affected parties include bicyclists, motorists, and residents of the surrounding area. The Federal Highway Administration (FHWA) recommends conducting a visual impact analysis (VIA) to study the change in continuity of a scenic view due to the introduction of a man-made object. Visual transparency was also identified as an important factor in railing design guidelines. Other research material identified the importance of context sensitive design and studying the surrounding landscape when implementing a bridge project. Good design and engineering judgment should be used to blend the bridge into the landscape in all environments. Recommendations include maximizing the view from the bridge through flexibility in railing design. The design should take into consideration the varying amount of time required for bicyclists to cross the bridge. Chapter 5 provides a moredetailed summary of aesthetics and railing design. Additional resources listed average heights of adult males and females and children, including eye-level heights of motorists, and heights of bicyclists and pedestrians. These heights help determine the ability to see over a railing along a bikeway or traffic barrier within mountainous terrain. Chapter 3, “The Design Bicyclist,” summarizes human dimensions and provides center-of-gravity analyses. The literature review revealed that bicycle crash data involving railings is not a widelyreported event. Crash surveillance systems and informational guides were investigated, including the National Center for Statistics and Analysis (NCSA) Fatality Analysis <strong>Report</strong>ing System (FARS), North Carolina Department of Transportation’s Division of <strong>Bicycle</strong> and Pedestrian Transportation <strong>Bicycle</strong> and Pedestrian Crash Web-database, and the FHWA “<strong>Bicycle</strong> Crash Types Information Guide.” Chapter 5 discusses the limitations of available crash data in greater detail. To supplement the literature review, a bicycle railing height survey was provided to state bicycle coordinators, bicycle advocates, and bridge engineers. The survey questioned respondents regarding railing height practices, and solicited information regarding crash 3
DETERMINATION OF APPROPRIATE RAILING HEIGHTS FOR BICYCLISTS NCHRP 20-7 (168) events and data. Chapter 4 provides a summary of the survey, and Appendix A presents the state and advocacy group bicycle survey and responses. 4
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5-3. Did the bicyclist fall over th
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BICYCLE RAILING HEIGHT SURVEY STATE
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BICYCLE RAILING HEIGHT SURVEY ADVOC
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2-6. What was the serverity of the
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APPENDIX B
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Bicycle Railing Height Report - AASHTO - Subcommittee on Design

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