Pedestrian crossing location and treatments

Pedestrian crossing locations at roundabouts are a balance among pedestrian convenience, pedestrian safety, and roundabout operations:

• Pedestrian convenience: Pedestrians want crossing locations as close to the intersection as possible to minimize out-of-direction travel. The further the crossing is from the roundabout, the more likely that pedestrians will choose a shorter route that may put them in greater danger.
• Pedestrian safety: Both crossing location and crossing distance are important. Crossing distance should be minimized to reduce exposure of pedestrian-vehicle conflicts. Pedestrian safety may also be compromised at a yield-line crosswalk because driver attention is directed to the left to look for gaps in the circulating traffic stream. Crosswalks should be located to take advantage of the splitter island; crosswalks located too far from the yield line require longer splitter islands. Crossings should also be located at distances away from the yield line measured in increments of approximate vehicle length to reduce the chance that vehicles will be queued across the crosswalk.
• Roundabout operations: Roundabout operations (primarily vehicular) can also be affected by crosswalk locations, particularly on the exit. A queuing analysis at the exit crosswalk may determine that a crosswalk location of more than one vehicle length away may be required to reduce to an acceptable level the risk of queuing into the circulatory roadway. Pedestrians may be able to distinguish exiting vehicles from circulating vehicles (both visually and audibly) at crosswalk locations further away from the roundabout, although this has not been confirmed by research.

With these issues in mind, pedestrian crossings should be designed as follows:

• The pedestrian refuge should be a minimum width of 1.8 m (6 ft) to adequately provide shelter for persons pushing a stroller or walking a bicycle (see Section 6.2.3).
• At single-lane roundabouts, the pedestrian crossing should be located one vehicle- length (7.5 m [25 ft]) away from the yield line. At double-lane roundabouts, the pedestrian crossing should be located one, two, or three car lengths (approximately 7.5 m, 15 m, or 22.5 m [25 ft, 50 ft, or 75 ft]) away from the yield line.
• The pedestrian refuge should be designed at street level, rather than elevated to the height of the splitter island. This eliminates the need for ramps within the refuge area, which can be cumbersome for wheelchairs.
• Ramps should be provided on each end of the crosswalk to connect the crosswalk to other crosswalks around the roundabout and to the sidewalk network.
• It is recommended that a detectable warning surface, as recommended in the Americans with Disabilities Act Accessibility Guidelines (ADAAG) §4.29 (Detectable Warnings), be applied to the surface of the refuge within the splitter island as shown in Exhibit 6-26. Note that the specific provision of the ADAAG requiring detectable warning surface at locations such as ramps and splitter islands (defined in the ADAAG as “hazardous vehicle areas”) has been suspended until July 26, 2001 (ADAAG §4.29.5). Where used, a detectable warning surface shall meet the following requirements (7):
  • The detectable warning surface shall consist of raised truncated domes with a nominal diameter of 23 mm (0.9 in), a nominal height of 5 mm (0.2 in), and a nominal center-to-center spacing of 60 mm (2.35 in).
  • The detectable warning surface shall contrast visually with adjoining surfaces, either light-on-dark or dark-on-light. The material used to provide contrast shall be an integral part of the walking surface.
  • The detectable warning surface shall begin at the curb line and extend into the pedestrian refuge area a distance of 600 mm (24 in). This creates a minimum 600-mm (24-in) clear space between detectable warning surfaces for a minimum splitter island width of 1.8 m (6 ft) at the pedestrian crossing. This is a deviation from the requirements of (suspended) ADAAG §4.29.5, which requires a 915-mm (36-in) surface width. However, this deviation is necessary to enable visually impaired pedestrians to distinguish the two interfaces with vehicular traffic.

In urban areas, speed tables (flat-top road humps) could be considered for wheelchair users, provided that good geometric design has reduced absolute vehicle speeds to less than 20 km/h (12 mph) near the crossing. Pedestrian crossings across speed tables must have detectable warning material as described above to clearly delineate the edge of the street. Speed tables should generally be used only on streets with approach speeds of 55 km/h (35 mph) or less, as the introduction of a raised speed table in higher speed environments may increase the likelihood of single-vehicle crashes and is not consistent with the speed consistency philosophy presented in this document.