Abstract
The study concludes that the most appropriate control system should include .changeable message signs, variable direction signs, automatic detection of traffic incidents and bad weather, supplemented by area broadcasts of traffic information, to ensure that information for drivers is always given in the same manner, it is proposed that new symbols should be adopted to warn drivers of hazards encountered on high-speed roads, that light-matrix changeable message signs should be sanctioned, and that radio messages should always have the same sequential structure.