Module D - Slide 3


MUTCD does provide some guidance on where to install APS, but this may be inadequate in light of ADA requirements. A jurisdiction can still be sued for discriminating under ADA, even if following MUTCD. The MUTCD says that an engineering study should be done and should consider the following factors: potential demand – in other words, the likelihood that a pedestrian who is blind would be at that location; a request; traffic volumes, including low traffic volumes; the complexity of traffic signal phasing and the complexity of intersection geometry.

If you think back to Module 2, why do you think that low traffic volumes matter? Remember that people who are blind use the sound of cars starting to move beside them, the “surge” of traffic, so locations with low traffic volumes may not have any good cues to the time the signal changes. And how about complexity of signal phasing? Again it has to o with being able to recognize the surge of traffic. In the case of complex phasing, it’s picking out the right surge at the right time and not confusing it with other traffic movement. And the complexity of intersection geometry has to do with the need for more information about geometry, which is hard to determine by listening.

The 2009 MUTCD added more about what is meant by complexity of signal phasing by adding the parenthetical phrase: such as split phases, protected turn phases, leading pedestrian intervals, and exclusive pedestrian phases.