Effects on Road Safety and Functionality of Installing Countdown Timers to Traffic Lights

In this paper it is surveyed whether the installation of countdown timers to the traffic lights of an urban intersection can efficiently contribute to the increase of both road safety and traffic capacity of the converging streets. A complete case-study is conducted in the city of Komotini (67,000 inhabitants, north-eastern Greece). By using video monitoring devices and the software Captiv L2100 the behavior of 14,946 drivers in two intersections in the center of the city under study is monitored. The analysis focused on their behavior just before the change of the traffic lights to green and red ones. It is concluded that installation of such devices leads to reduction of delays and increase of traffic capacity. However, concerning safety, drivers have a contradictory behavior. They respect the coming of the red light, while they begin moving before the green light is on. Under these findings, it is suggested to use the specific device before the light turns to red, but not before the light turns to green.

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