Study Tests Devices to Improve Work Zone Safety

The Texas Department of Transportation (TxDOT) selected the Texas Transportation Institute (TTI) to investigate new traffic control devices that can improve worker and driver safety. This study attempted to identify devices that would better alert drivers to work zone conditions and motivate them to change the way they drive within the work zone. The speed display trailer was the most effective traffic control device tested to control speed in a work zone. Drivers slowed an average of 5 mph in the work zone after passing a speed display trailer. The key advantage of these trailers is that they are easy to set up and dependable. They also have a 130 dB siren that can be activated by vehicles traveling over a preset speed. The siren warns the maintenance crew if a vehicle is approaching at a very high rate of speed. Fluorescent yellow-green vests and hard hat covers greatly improved worker visibility. These devices are more visible against typical work zone backgrounds and have a greater luminance than the traditional orange garments. The yellow-green safety vests were shown to greatly increase the visibility of the flaggers and maintenance crews and are currently being distributed to TxDOT personnel.