Ask The City: Harney Traffic Lights
Why are the traffic lights on Harney setup the way they are? If someone is turning left one direction and there is no one sitting at the red light in the other than the signal skips that direction's turn. I understand the logic behind the turn signal being green first but why the skip? This to me seems to encourage people racing to red lights which is more dangerous than slowing as you approach the light.
“This is to help traffic move as easily as possible. With the camera detection if no one is in the opposing lane it lets the person waiting go. If there are people in the turn lane and there are vehicles in the oncoming lane going straight it lets the straight traffic go first then if needed gives a green arrow at the end of the cycle. The detection is setup to allow for the best flow of traffic depending on the situation of vehicles at the signal.
There is also a time cut off where a vehicle has to be detected prior to this point in the cycle change or it won’t service that movement and the signal will switch to the other phase. If a vehicle gets there late they will have to wait through one cycle to be serviced as the controller has to have sufficient time to process the changes so it establishes a cut off limit after which no changes (vehicle detections) to the cycle can be made. It amounts to about a minute’s worth of delay.”