278 Chapter 11
Title III stipulates that in new construction at least one TTY is to be provided inside any building that
has four or more public pay telephones (counting both interior and exterior phones). A TTY must also be
provided whenever there is an interior public pay phone in a stadium, convention center, hotel with a
convention center, covered shopping mall, or hospital emergency, recovery, or waiting room. Title III
also stipulates that one accessible public phone must be provided for each floor of new construction, un-
less the floor has two or more banks of phones, in which case one accessible phone should be provided
for each bank.
Protruding Objects.
There are restrictions on objects and building elements that project into corridors and other walkways,
because they present a hazard for visually impaired people. There are no restrictions on protruding ob-
jects where their lower edge is less than 27 inches (686 mm) above the floor, because these can be de-
tected by a person using a cane. However, protruding objects cannot reduce the clear width required for
an accessible route or maneuvering space, and a guardrail or other barrier must be provided for areas
adjacent to accessible routes where the vertical clearance is reduced to less than 80 inches (2 m).
Signage and Alarms.
Signage should give clear guidance for visually impaired people to emergency information and general
circulation directions. Of importance in evaluating signage criteria is the ability to be viewed by people
with low vision (20 percent of normal) from a distance of 30 feet (9.14 m). Signage is also required for
elevators and handicapped-accessible entrances/exits, toilets, and other locations. For optimum clarity,
adequate luminescence should be provided. Contrasting colors can also enhance legibility—70 percent
or more contrast between letters and background is recommended.
The ANSI standards specify the width-to-height ratio of letters and how thick the individual letter
strokes must be. They also require that characters, symbols, or pictographs on tactile signs be raised
1/32 inch (0.79 mm). If accessible facilities are identified, the international symbol of accessibility must
be used (Figure 11.13). Braille characters must be Grade 2.
The ADA Accessibility Guidelines 4.1.3(14) state that, if emergency warning systems are provided,
they shall include both audible alarms and visual alarms complying with 4.28. Audible alarms must pro-
duce a sound that exceeds the prevailing sound level in the room or space by at least 15 decibels. Vi-
sual alarms must be flashing lights that have a flashing frequency of about one cycle per second.
Elevators and Elevator Cars.
All elevators must be accessible from the entry route and all public floors and must comply with the ap-
plicable codes for elevators and escalators. Elevators must be provided with handrails fixed 32 inches
above the floor on all three sides of the cab. Minimum cab size should be 67 inches (1.7 m) to allow a
wheelchair to maneuver (Figure 11.14). Both visual and audible hall signals are important to inform ele-
vator passengers where an elevator is and in which direction it is going. This is particularly important at
elevator banks comprising more than one car. Elevator controls should comply with ANSI A117.1 stan-
dards regarding visual, tactile, and audible controls.