Recommendations, Characteristics of Emerging Road and Trail Users and Their Safety, FHWA-HRT-04-103

RECOMMENDATIONS

The data collected for this study reveals that the appropriate design user for shared use paths may vary with respect to design criteria or a facility design element. Table 23 shows design features, AASHTO design values for bicyclists, potential design users, and 85^th percentile performance values.

Table 23. Design criteria and potential design users.

DESIGN FEATURE	AASHTO DESIGN VALUE (FOR BICYCLISTS)	POTENTIAL DESIGN USER	PERFORMANCE VALUE (85TH PERCENTILE)
Sweep width	1.2 m	Inline skaters	1.5 m
Horizontal alignment	27 m	Recumbent bicyclists	26.8 m
Stopping sight distance (wet pavement)	38.7 m	Recumbent bicyclists	32.7 m
Vertical alignment-crest	49.8 m	Recumbent bicyclists	46.7 m
Refuge islands	2.5 m	Bicyclists with trailers	3.0 m
Signal clearance intervals	7.5 sec for a distance of 24.4 m	Kick scooters	10.6 sec for a distance of 24.4 m
Minimum green times	12.8 sec for a distance of 24.4 m	Hand cyclists	17.9 sec for a distance of 24.4 m
Pedestrian clearance intervals	20.0 sec for a distance of 24.4 m	Manual wheelchairs	15.4 sec for a distance of 24.4 m

1 m = 3.28 ft

It is worth noting that bicyclists (without trailers) do not appear as critical users for any of the design criteria. This is a major finding that may have a significant effect on how shared use paths and other components of the U.S. transportation system are designed, constructed, controlled, and maintained.

The data collected during this project suggest that several actions should be considered:

The results of this study should be disseminated to design professionals and shared use path operators for their review and comments.
A 1-day presentation should be made to, and discussed with, an expert panel of facility design engineers.
A new NHI course should be developed (or the existing courses should be significantly modified).
An interim FHWA design guide for shared use paths should be developed.
The AASHTO Guide for the Development of Bicycle Facilities should be updated to reflect this research's findings on bicycles.
An AASHTO document on shared use path design guidelines should be developed. For further details, see the following marketing plan.

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FHWA-HRT-04-103

HRDS-06/10-04(1M)E

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