Originally Posted by sggoodri

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Since traffic engineers often do not want to delay arterial traffic for such a long time when there is no pedestrian present, they usually employ ped detectors and only provide the ped signal with clearance interval when the button is pressed. Usually the only resistance to this by the engineers is money. But I've seen NCDOT refuse to do this even when the city offered to pay, because the NCDOT engineer didn't want to provide safe timing for pedestrians even when they were detected, and believed that not providing the signal would discourage pedestrians from crossing, which would be good for motorists on the arterial. Needless to say, such engineers get a real earful from me.

Note that activating a pedestrian signal increases the green time for vehicular traffic on the side street. It may not be possible to activate the ped signal and then get back in line with traffic, but sometimes a ped signal is the only way to stop arterial traffic long enough to cross safely.

There are a number of sensor configurations and signal settings that can be used to detect the length of the queue at cross streets and provide a longer green time for vehicle traffic as required. California has been studying ways to automatically detect the speed that vehicles clear intersections, or to detect bicycles specifically, to ensure adequate clearance time. Again, the lack of deployment of solutions mostly about money.