Bicycle Railing Height Report - AASHTO - Subcommittee on Design

DETERMINATION OF APPROPRIATE RAILING HEIGHTS FOR BICYCLISTS
NCHRP 20-7 (168)
Correspondence and survey responses were received from Canada, Australia,
Netherlands, and England. Their adopted bicycle railing heights include:
• Canada’s “Highway Bridge Design Code” recommends a 1.4-meter (55-inch)
railing height on bridges for bicyclists.
• Australia’s “Guide to Traffic Engineering Practice – Part 14 <strong>Bicycle</strong>s”
recommends a bicycle railing height of 1.4 meters (55 inches).
• Danish Road Directorate’s “Collection of Cycling Concepts” contains guidelines
for a bicycle railing height of 1.2 meters (47 inches).
• Hampshire, England’s recommended minimum railing height for barriers on a
bridge is 1.5 meters (59 inches).
State and Local Guidelines
An analysis of the survey revealed that some states do not strictly adhere to the <strong>AASHTO</strong>
Bridge Guidelines requirement for a 1.4-meter (54-inch) high bicycle railing. Of the 28
states responding, 68% (19 states) indicated that they use a 1.4-meter (54-inch) bicycle
railing height on bridges, while 18% (5 states) indicated that they use a 1.1-meter (42-
inch) bicycle railing height. Four states (14%) indicated that their selection varies
depending on project conditions. <strong>Height</strong>s of 32 inches (0.8 meters) and 45 inches (1.15
meters) were also identified.
The survey revealed that out of the 28 states responding, 25% use a bicycle railing height
of 1.4 meters (54 inches) along a bicycle path, while 61% use a bicycle railing height of
1.1 meters (42 inches). Two states indicated that the heights of bicycle railings are
project-driven or determined by environmental conditions.
Table 1 lists the state-adopted bicycle and bridge railing
heights of the 28 responding states. Some states noted that
bicycle railing heights were determined based on the
physical conditions surrounding the bicycle facility, such
terrain, snow conditions (shared use paths use by skiers in
the winter), drop-off height, etc. A complete listing of the
comments received can be found in Appendix A.
The “Design Bicyclist”
<strong>Bicycle</strong> railing height design decisions in the 1970s were
based on the theory that railing heights must be higher than
a bicyclist’s center of gravity (COG). As such, highway
officials conservatively adopted a 1.4-meter (54-inch)
height. However, this approach and theory is widely
disputed since, to date, no scientific study has concluded
that the COG of a bicyclist is the key factor in railing height
determination.
Figure 6 - Bicyclist Operating
Space
Source: <strong>AASHTO</strong>, “Guide for
the Development of <strong>Bicycle</strong>
Facilities,” 1999
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