Federal Way’s yellow light time is 4.0 seconds with a one second all red time (all the lights are red before the next green light occurs). In autumn 2008, Chillicothe, Ohio, had an in-depth study on red light infractions. They showed at a 40 mph intersection that increasing the yellow light time from varying between 3.3-3.8 seconds to 4.9 seconds decreased red light infractions by 97 percent. When a light turns yellow, motorists have a split second to decide to stop or accelerate, the “dilemma zone.” Some of the study’s conclusions included:
• All red durations, when long enough, can be properly set to clear the intersection and avoid T-bone accidents.
• Dilemma zones prevent motorists from coming to a safe stop, increase the risk of rear-end collisions, force them to “run the red light,” or force them to exceed the posted speed limit.
• Yellow durations should be properly set to eliminate dilemma zones.
• Dilemma zones are the most likely reason for an increased rate of rear-end collisions at camera intersections.
• Properly timed traffic signals eliminate dilemma zones.
• Properly timed traffic signals nearly eliminate “Red Light Running.”
• A relationship exists between the length of the yellow light and the number of tickets produced. A shorter yellow produces more tickets, and a longer yellow produces few tickets.
• In summary, dilemma zone provide motorists the following three choices: slam on the brakes and risk a rear-end accident, continue through the intersection and be issued a “red light” infraction, or speed up and be issued a speeding infraction. These options are neither safe nor acceptable, and they carry a financial consequence for the motorist as well.
If this is truly about safety, I would propose that the city study at its camera intersections increasing the yellow light time to 4.9 seconds. It can also study increasing the all red time, perhaps to 2 seconds, especially at large intersections. Based on the above study, there is an excellent likelihood that red light infractions and rear end collisions would decrease by solely increasing the yellow light time. Considering that the S. 348th Street and Enchanted Parkway intersection is seven lanes wide north/south and nine lanes wide east/west, it probably would be prudent study increasing the all red time beyond one second.
Federal Way can, if it wants, study traffic light timing changes at its red light revenue generator intersections. I would hypothesize that safety would be greatly increased. You won’t even need to wait for the study’s results to know the answer. American Traffic Solutions will remove the cameras as totally unprofitable. Will the city do it? I won’t hold my breath waiting.
Let’s be honest about this. This is not about public safety. This is about money. That is why I referred to Federal Way’s photo cop red light cameras for what they really are, Federal Way’s red light revenue generators.
Mark Sebastian, Federal Way