¥Not
only are the yellows too short, what about the safety of those within the
intersection.
¥November 1985 -
"In a recent paper, Parsonson and Santiago reviewed a liability suit in
which the City of Flint, Michigan,
was held responsible for the wrongful death of a driver who died in a
crash when his car was hit by a truck at an intersection
with an inadequate yellow phase and no all-red phase. The authors of that
paper warned the traffic engineering profession that "the traditional design standards for timing of the clearance period (yellow plus
all-red) for traffic signals are inappropriate and
unreasonable in some important aspects. They can yield values that are too short for safety...." The
paper then recommended improved design procedures
"which the engineer would feel more comfortable defending in court." ..... "This project has
shown that even the currently accepted
practices are commonly ignored and that clearance intervals that are too short are statistically associated with larger than
average crash rates. These results and the Flint
case should serve to further underline the need to adopt improved clearance interval timing procedures
throughout the nation." ["Effect
of Clearance Interval Timing on Traffic Flow and Crashes at Signalized
Intersections", Zador/Stein/Shapiro/Tarnoff, ITE Journal, November 1985, pgs
36-39]