Traffic information and driver attention: A study of variable message signs and their effects on driving behaviour

Traffic signs may possibly distract road users and disturb traffic flow if the information is difficult to perceive fast enough. Effects of variable-message signs were investigated by recording speed changes and braking before signs with and without a message. Average speeds decreased and the proportion of braking drivers increased when there was a message on the sign.This may indicate that the legibility was insufficient, so that the drivers did not perceive the information quickly enough. Further studies are suggested, in order to find the optimal design and positioning of signs in order to avoid potentially hazardous braking. This may also yield useful knowledge about necessary reading times for traffic information more generally.