One of my wonderful questioners from California sent me pictures so I can
discuss two of my major concerns about crossings at intersections, crosswalks,
and parking lots.
Concern No. 1: The law's very first directive required
detectable warnings to be the length of curb ramps. But after further study, the
new design directive (Public
Rights-of-Way Accessibility Guidelines 2005, Section R304.1.4) from both the
Access Board and Federal Highway Administration
which is supported by the Department of Justice, says the warning should be a
minimum of 2 feet long and the full flat width of the ramp, landing, or blended
Concern No. 2: Even though detectable warnings at curb ramps
aren't intended to indicate direction, sometimes the warning and ramp's position
together unintentionally confuse a visually impaired person about the crossing's
The following pictures should help you understand these issues:
Images A, B, and C: The detectable warnings at all three of
these sidewalks extend the ramp's full length. As a wheelchair and former
crutches user who deals with chronic pain, I can personally attest that it's
physically excruciating to navigate these bumpy crossings.
The Access Board's Public Rights of Way subcommittee shortened the length to
2 feet because other similarly afflicted people lodged the same complaint.
Plus, a 2-foot design is less expensive.
Images B — E: Another common problem (as shown in images B
and C above) is the radical change of direction that sometimes occurs between
the crosswalk and the curb ramp. How is a person with severe vision limitations
to know that the crosswalk lies in a totally different direction than the curb
Images D and E below are examples of directional guides that a person with a
cane can use to follow the crosswalk's path. Such aids cost less than an
extended directional warning, giving you a positive benefit/cost ratio. Note
that the pavers are (as they should be) located on the outside of the actual
crosswalk instead of in the actual path.
Images F and G: Last but not least, let’s look at locations
of curb ramps in parking areas. In example F, depending on vehicle size or
parking approach, the crosswalk can easily be obstructed. This is confusing for
those with limited vision and potentially impassable for wheelchair users.
Example G shows a poorly thought-out plan: The ramp is completely obstructed
by the parked vehicle.
Please seriously consider your end-users as you design, retrofit, and layout
To understand a wheelchair user's needs, just go out with a folding chair and
place yourself in the path you are designing. Or, to understand a user with
visual impairments, blindfold yourself and have someone turn you about like you
would in the game "pin the tail on the donkey," and then try to follow the path
you are laying out for others to use.
Thanks to R. Fillmore Grefe, PE, for the pictures illustrating extended
detectable warning strips and abrupt changes of direction at crosswalks.
Until next month, I hope all of you have dug yourselves out of the snow!