In the past, when significant events or incidents led to closure of sections of motorway or trunk road, traffic was simply directed on to local roads therefore causing drivers to find their own way back onto the strategic road network. This regularly caused congestion on all routes within the area as well as disruption to local businesses and residents.
Emergency Diversion Routes (EDRs) help the Highways Agency manage traffic after closure of its network. For example, when a main carriageway is closed due to a serious incident, we have in place nearly 2000 pre-planned, checked and agreed junction to junction diversion routes that circumnavigate the closed sections.
Wayne Norris, of the Highways Agency, Network Management Group says: "Since May 2006 we have worked with Local Authorities to develop and implement the most effective diversion routes. We can now direct traffic on to these agreed and signed routes, minimising congestion on other local roads."
Before proposing EDRs, the Agency investigates each possible route for suitability, identifying traffic 'pinch points' such as low or weak bridges, schools, hospitals, large retail outlets, sports and entertainment venues and main commuter routes. Once agreed by local authorities, signs are put in place.
The EDR signs use standard black shapes on a yellow background, with trigger signs on the motorway and at other key points, indicating the symbol to be followed for each diversion route. In most cases, the symbols are added to existing signs as shown below:
A number of different symbols are used, as in some places there may be more than one diversion operating. The range of symbols used is shown below:
Stefan Milczarek of the Highways Agency adds: "We are now talking with external providers to push our driver’s education campaign forward. We are working closely with the Driving Standards Agency and other organisations to achieve better understanding of diversion routes and the symbols used."