Characteristics of Emerging Road and Trail Users and Their Safety

Width

The AASHTO Guide for the Development of Bicycle Facilities (p. 5) recommends a minimum width of 120 cm (48 inches) for any facility designed to be used by bicyclists.⁽²⁾ This is based on a typical bicyclist having a width of 75 cm (30 inches) and requiring a minimum of 100 cm (40 inches) of operating space. Table 9 shows that the mean width for bicyclists in this study was 61 cm (24 inches), and the 85^th percentile width was 69 cm (27 inches). Hence, the values observed for bicyclists seem consistent with the AASHTO value.

Among equipment types with five or more users, hand cyclists appear to be the critical user, as they had the highest mean (65 cm (26 inches)) and 85^th percentile (71 cm (28 inches)) widths. For all user types with five or more users, the 85^th percentile width was less than 75 cm (30 inches). Thus, the AASHTO value accommodates above 85 percent of the observed individuals within each user type.

Section 4.2.1 of the ADAAG requires a minimum clear width of 81.5 cm (32 inches) at a point, and 91.5 cm (36 inches) continuously, for single wheelchair passage. All of the "solo" manual and power wheelchair users (i.e., not accompanied by a dog or pulling another wheelchair) had widths of 69 cm (27 inches) or less, and would therefore be accommodated by ADAAG.

^2. American Association of State Highway and Transportation Officials. Guide for the Development of Bicycle Facilities. American Association of State Highway and Transportation Officials, Washington, DC, 1999.

Table 9. Width.

NOTES:
1. This table includes only active participants.
2. AASHTO value for a facility designed to be used by bicyclists = 120 cm (48 inches)
3. NA = Not applicable because N=1.