There are 25 traffic signals in Marshalltown that the city oversees.  Whether those are pedestrian crosswalks, school crossing flashing beacons, or your typical street traffic signal.  There are different ways that these street traffic signals sense a vehicle.

That is David Demeer, the City of Marshalltown Electrical and Facilities Superintendent.  He oversees all the traffic signals in Marshalltown.  Demeer explains about how long it will take for a red light to switch after the sensor senses a vehicle.

Demeer says the timer starts once the sensor is covered or a car is in camera frame.  Once the car leaves frame or is no longer on top of the sensor, the timer stops and will restart when the sensor is again triggered.

Zach Tomesch, News Director KFJB