Safety
Does dynamic route information influence road safety?
Studies of the effects of DRIPs giving information about the traffic distribution on the Amsterdam main road network show that the introduction of new DRIPs have resulted in slower and more homogeneous speeds, but that this had no large positive effect on the number of road crashes. Simulation research of dynamic route guidance shows that only limited road safety effects are to be expected. International research of electronic tailgate warning systems shows a reduction in injury crashes and an increase in material damage only crashes. The latter is probably caused by motorists changing lane more frequently and leaving the motorway more often.
DRIPs may cause traffic moving from the main road network to secondary roads (rat-run traffic). If no additional measures are taken, we expect that this will be accompanied by an increase in road crash casualties because the crash rate on secondary roads is greater.
DRIPS that show general safety information are not a dangerous distraction to drivers.