Pedestrians

As was described previously, vehicular injury crashes normally decrease when roundabouts are installed at an existing intersection. The safety benefits of roundabouts have been found to generally carry over to pedestrians as well, as shown in British statistics of Exhibit 5-15. This may be due to the reduced speeds at roundabouts as compared with the previous intersection forms.

For pedestrians, the risk of being involved in a severe collision is lower at roundabouts than at other forms of intersections, due to the slower vehicle speeds. Likewise, the number of conflict points for pedestrians is lower at roundabouts than at other intersections, which can lower the frequency of collisions. The splitter island between entry and exit allows pedestrians to resolve conflicts with entering and exiting vehicles separately.

A Dutch study of 181 intersections converted to roundabouts (4) found reductions (percentage) in all pedestrian crashes of 73 percent and in pedestrian injury crashes of 89 percent. In this study, all modes shared in the safety benefits to greater (passenger cars) or lesser extents (bicycles), as shown in Exhibit 5-16.

A risk analysis of 59 roundabouts and 124 signalized intersections was carried out on crash data in Norway between 1985 and 1989. Altogether, 33 crashes involving personal injury were recorded at the 59 roundabouts. Only 1 of these crashes involved a pedestrian, compared with the signalized intersections, where pedestrians were involved in 20 percent of the personal injury crashes (57 of 287 injury crashes) (16).

Further, there is no quantitative evidence of increased safety for pedestrians at roundabouts with striped (zebra) crossings, where pedestrians have priority. Therefore, striped crossings have generally not been used in other countries. However, in the U.S., it is recommended that all crosswalks be striped except at rural locations with low pedestrian volumes. Although this is not their intended function, striped crosswalks may further alert approaching drivers to a change in their appropriate speed near the yield point.

Crash data have not been collected to indicate whether a pedestrian has a disability, and no studies have focused specifically on the safety of visually impaired pedestrians at roundabouts. This is an area requiring further research.

Information access for blind or visually impaired pedestrians

Roundabout crossing skills may be difficult for disabled pedestrians to perform without assistance. For example, audible pedestrian-activated signals may be considered on an approach, although this treatment is not typical. Any leg of any roundabout could be equipped with a pedestrian-activated signal at the pedestrian crossing, if a balanced design requires providing assistance to pedestrians at that location. For example, motorized volume that is too heavy at times to provide a sufficient number of gaps acceptable for pedestrians may warrant a pedestrian signal equipped with audible devices to assist people with visual disabilities.

When crossing a roundabout, there are several areas of difficulty for pedestrians who are blind or visually impaired. It is desirable that a visually impaired pedestrian with good travel skills should be able to arrive at an unfamiliar intersection and cross it with pre-existing skills and without special, intersection-specific training. Roundabouts pose problems at several points of the crossing experience, from the perspective of their access to information:

• The first task of the visually impaired pedestrian is to locate the crosswalk. This can be difficult if the roundabout is not properly landscaped and if the curb edge of the ramp is not marked with a detectable warning surface (see Chapter 6). The crosswalk direction must also be unambiguous. Zebra-stripe markings are recommended at most roundabouts to indicate pedestrian crossings. Safety of visually impaired pedestrians at roundabouts requires further research. Challenges that roundabouts pose to visually impaired pedestrians.
• Depending upon whether the visually impaired pedestrian is crossing the roundabout in a clockwise or counterclockwise direction, they must listen for a safe gap to cross either the entrance or exit lane(s). The primary problem is the sound of traffic on the roundabout, which may mask the sound of cars approaching the crosswalk. While crossing the exit lane poses the greater hazard to the pedestrian who is visually impaired because of the higher speed of the vehicles, crossing the entrance may also pose significant problems. Entering traffic, while slower, may also be intimidating as it may not be possible to determine by sound alone whether a vehicle has actually stopped or intends to stop. Sighted pedestrians often rely upon communication through eye contact in these situations; however, that is not a useful or reliable technique for the pedestrian who is visually impaired. Both these problems are further exacerbated at roundabouts with multilane entrances and exits. In these roundabouts, a stopped car in the near lane may mask the sounds of other traffic. It may also block the view of the driver in the far lane of the cane or guide dog of a person who is visually impaired who begins to cross (this is also a problem for children and people using wheelchairs on any crossing of a multilane road).
• The third task is locating the splitter island pedestrian refuge. If this refuge is not ramped, curbed, or equipped with detectable warnings, it is not detectable by a pedestrian who is visually impaired.
• Crossing the remaining half of the crossing (see the second bullet above).
• Locating the correct walkway to either continue their path or locate the adjacent crosswalk to cross the next leg of the roundabout.

Unless these issues are addressed by a design, the intersection is “inaccessible” and may not be permissible under the ADA. Chapters 6 and 7 provide specific suggestions to assist in providing the above information. However, more research is required to develop the information jurisdictions need to determine where roundabouts may be appropriate and what design features are required for people with disabilities. Until specific standards are adopted, engineers and jurisdictions must rely on existing related research and professional judgment to design pedestrian features so that they are usable by pedestrians with disabilities.

Possible design remedies for the difficulties faced by pedestrians include tight entries, raised speed tables with detectable warnings, treatments for visually impaired pedestrians to locate crosswalks, raised pavement markers with yellow flashing lights to alert drivers of crossing pedestrians, pedestrian crossings with actuated signals set sufficiently upstream of the yield line to minimize the possibility of exiting vehicle queues spilling back into the circulatory roadway (6). However, the safety of these treatments at roundabouts has not been tested in the United States.