In Newport, RI, where narrow brick sidewalks in a historic downtown offer few locations
for curb ramp installation, planners have proposed to raise the crosswalks to curb height
in order to provide barrier-free crossing at major intersections. This solution also has a
traffic-calming effect, but has raised concerns among blind residents about the
detectability of the street edge.
Cumberland, MD’s downtown pedestrian mall employs raised crosswalks at cross streets,
slowing the speed of vehicles at these intersections, where cars--not pedestrians--must
ramp up to, across, and down. Such ‘speed tables’ can be effective traffic calming
devices, but do not provide notice to blind pedestrians of the boundary between
pedestrian and vehicular areas. The Access Board recommends that detectable warnings
be installed at such intersections.
California’s accessibility regulation, title 24, requires a 24-inch-wide strip of detectable
warning material where sidewalks enter a roadway without an intervening curb face.
Several other states, including Florida and New Jersey, have adopted codes requiring
detectable warnings. Austin, TX requires detectable warnings on all new curb ramps.
Australia, Great Britain, and Japan have longstanding requirements for tactile surfaces.
The International Standards Organization (ISO) is currently developing a standard for
tactile pedestrian indicators. The ADAAG detectable warnings provision has been
temporarily suspended for sidewalk applications, but is required at transit platforms.