Summary: Evaluation of different retro-reflective traffic signs

Within this study, done within the Austrian Road Safety Board, two different retro-reflective materials on traffic signs were analysed with regard to potential impact on gaze duration in real night-driving circumstances. 63 test subjects had to drive a pre-defined route simultaneously solving two tasks. Signs laminated with the higher retro-reflectivity were beingh looked at significantly shorter thus allowing for less eyes-off-the-road time.

Scope

The aim of this field study was to analyse several eye movement characteristics at two different laminated retro-reflective traffic signs with regard to their specific impact on gaze duration in real night-time driving situations.

Method

The results were based on 63 subjects and were derived from an in-vehicle observation system. The dependent variables were first and last glance distances to signs as well as gaze duration at signs. During the test drive, subjects had to solve an action task, where test persons had to look at specific targets inside the vehicle, depending on the titles of the traffic signs and a navigation task where subjects had to find their way through the test route, only relying on traffic signs and on rather vague instructions from a co-driver.

Results

Significant differences within the action task occurred with regard to last glance distances: eye movements deviated significantly earlier (approx. 8 meters) when looking at high retro-reflective sheeted traffic signs. Normally sheeted traffic signs were viewed significantly longer, on average about 0,3 seconds. Within the navigation task, no statistical differences occurred regarding visibility and correct behaviour. Generally, it can be concluded that the high retro-reflective sheeting material has a positive impact on observation behaviour and, in this manner on traffic safety itself. The information presented on traffic signs was perceived faster. Hence, drivers have potentially more time to concentrate on other essential stimuli in traffic.