Traffic monitoring gets smart

Ohio State University engineers have developed software for road traffic control boxes that can detect and notify authorities of accidents and congestion at a much lower cost.

Benjamin Coifman, associate professor of civil and environmental science and geodetic science at Ohio State, said that over the last few decades, US transport agencies had installed loop detectors to monitor traffic at key points on the road network.

The car-sized wire loops buried in the tarmac effectively act as metal detectors. When a vehicle passes over a loop, the detector sends a signal to a computer in a control box at the side of the road.

The controller may simply count the number of cars that pass by and calculate average speed, or it may actively control traffic, by operating a traffic light on a motorway slip road, for instance.

The main cost of using such devices is the that of sending electronic signals between them and the transportation centre that is doing the monitoring. Normally, controller boxes transmit their data very frequently, some as often as once every twenty seconds.