When my neighborhood near a university with lots of pedestrians found out we’ll probably get a roundabout, I was not pleased. It’s hard for blind people to cross whether we use canes or dogs because the traffic doesn’t stop and then surge which helps us know when to cross. So I did serious Internet research and came up with the following points. Feel free to borrow if you want to try to get your town’s traffic department to do roundabouts as well as possible. Traffic engineers love them, so I’m convinced “just say no” won’t work.

Analysis of problem: Requirements for Safe Crossing by Visually Impaired Pedestrians

The visually impaired pedestrian embarking on maneuvering a roundabout needs information about:

A. The location of cross walk which may be provided by:
• Landscaping, pedestrian barriers and other architectural features
• Standardized detectable strip across the sidewalk
• Curb ramps with returned edges aligned with crosswalk direction
• Sufficiently steep curb ramp slope to be detected underfoot
• Aligning the slope of the ramp with the crosswalk
B. The location of splitter island
• Signal the presence of a pedestrian refuge
• Detectable warnings mark the beginning and end of a safe pedestrian area
• About 60 cm of detectable warning surface is required
C. Crossing direction
• Remaining in the crosswalk
• Ultra-high contrast marking
• Raising or otherwise marking the crosswalk edges to provide a boundary
• Providing a raised guide strip at the centerline of the crosswalk
D. Safe crossing opportunities
• Likelihood of drivers giving way to pedestrians
• Crossing in front of stopped vehicle
• Stop bars and LED in-roadway warning lights
• Signals may be necessary to provide street crossing opportunities

Signals must optimize roundabout operations for both pedestrians and drivers.

Roundabouts may be unsuitable where there are large numbers of pedestrians.

The major design recommendations derived from the studies are:
• Ensure motorists recognize the approach to the roundabout.
• Avoid entries and exits with two or more lanes except for capacity requirements.
• Separate the exit and entry by a splitter (ghost) island.
• Avoid perpendicular entries or very large radii.
• Avoid very tight exit radii.
• Avoid oval shape roundabouts.

Advertisements