The development of active roadside traffic signs has been stimulated by the increasing requirement to provide real-time traffic information directly to road users. A wide range of new traffic management and advisory signs has been introduced in the Drive Time system, which VicRoads implemented in July 1995 on 15km of the busy South East Arterial highway in Victoria, Australia. This system was designed to provide drivers with real-time information, enabling them to make informed decisions about the use of the road and eventually to choose alternative routes. Data are continually collected from incident detection stations about 500m apart along the route. An algorithm predicts travel times between key locations, and estimates congestion levels for the road sections between them. Various road signs are used as one method of providing information to road users, at locations where it can be used effectively, in formats that are easy to understand. The most impressive signs on motorways are trip information signs. The displays are formed from 1m long sections of 200mm wide optical fibre matrix panels, whose colours can easily be switched. At traffic signal sites, ramp displays are co-ordinated with signal plans restricting turns onto the motorway. There are also motorway condition signs.
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