Some pedestrians fail to push available detector buttons and instead proceed to cross by observing the vehicle indications rather than the pedestrian indications. Since vehicles normally move faster than pedestrians, the green time needed to cross the intersection is less for a vehicle than for a pedestrian. If the detector is not used, the pedestrian indication remains at steady DON'T WALK, and the green time given by the vehicular signal is not always sufficient to permit a pedestrian to completely cross the roadway. When pedestrians do cross under these conditions, they are not only disregarding the traffic signal indications, and are violating Arizona Revised Statute 28-646, but they may come into conflict with a vehicle legally using the intersection, thus jeopardizing their own safety and the safety of others. The misconception that pedestrian signals and detectors automatically increase safety and should be installed at all signalized intersections.
Every signalized intersection has to be evaluated independently.
If the combination of signal timing, intersection layout, pedestrian volumes, and vehicular volumes are such that pedestrian signals and detectors are not needed, then they should not be installed. In addition to the substantial installation costs, pedestrian signals consume a significant amount of electrical power at a typical intersection. If the vehicular indications can safely accommodate pedestrian traffic, then there is no justification for spending scarce resources to install elaborate pedestrian controls. At some intersections it may be that only pedestrian detectors need to be installed. Where pedestrian volumes are low and pedestrian signals are not needed, a pedestrian detector can be used to extend the vehicular green, if it would otherwise be too short for a pedestrian to cross.