Bicycle Railing Height Report - AASHTO - Subcommittee on Design

DETERMINATION OF APPROPRIATE RAILING HEIGHTS FOR BICYCLISTS
NCHRP 20-7 (168)
length of the project, and vertical clearance under the structure. For example, an increase
in rail height creating a cost difference of $125 per linear meter ($22,500 total) on a 90-
meter (approximately 300-foot) long multi-span steel multi-girder bridge with an overall
price of $3,000,000 only represents 0.8% of the total project cost.
In summary, the difference in cost between a 1.1 meter (42 inch) and a 1.4-meter (54-
inch) high railing along one side of a shared use path is approximately $40 per linear
meter which represents approximately 15% of the cost of a shared use path.
The difference in cost of a four-rail 1.1 meter (42 inch) and a five-rail 1.4-meter (54-inch)
high combination railing on both sides of a bridge is approximately $125 per linear
meter, or less than one percent of the total cost of the bridge.
It is interesting to note here that the increase in cost of installing a combination pedestrian
railing instead of a bicycle railing is only an increase of approximately 80$ per linear
meter.
Additional Issues Related to <strong>Railing</strong>s
Respondents to the survey introduced several additional issues for consideration when
determining appropriate railing heights for bridges and bicycle paths. Additional factors
to consider include the affects of wind on the bicycle facility and the use of the facility by
equestrians and cross-country skiers.
Wind
In many coastal areas, bridges are key links in creating continuous paths. Bridges
provide bicyclists and pedestrians with the opportunity to experience spectacular land and
water views. However, bridges in coastal areas are exposed to different weather elements
(mainly related to wind exposure) than those located inland. Several respondents
indicated that a 1.4-meter (54-inch) high railing on coastal bridges protects bicyclists
from strong winds.
Equestrians and Cross Country Skiers
<strong>Railing</strong>s on shared-use paths could be inadequate
for the needs of equestrians and cross-country
skiers. An equestrian mounted on a horse is above
the normal height of a bicycle railing. Additionally,
individuals who participate in cross-country skiing
in areas of high snowfall tend to encounter
undersized or snow-buried railings. Respondents
indicated that the 1.4-meter (54-inch) railing was
more practical than a 1.1-meter (42-inch) railing on
shared-use paths that experience high snowfall
accumulations and active cross-country skiing use.
Figure 12 depicts a 1.2-meter (48-inch) railing in
Stowe, VT, reduced to 0.8 meters (30 inches) due to
Figure 12 - Bridge with Snow
Accumulation Source: Bruce Burgess
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