MOVING THE WHEELTRACKS

Concern at the cost of road pavement strengthening and the disruption caused by roadworks in the UK stimulated the Highways Agency to explore innovative measures for reducing the amount of strengthening maintenance required in the British trunk road network. The Agency inquired whether the life of a road could be extended by moving the position of a wheelpath within a traffic lane. Although loadings on a pavement tend to be concentrated in a very narrow wheeltrack, moving the positions of different vehicles could spread pavement wear over a wider section of traffic lane. A theoretical analysis indicated that the structural life of a flexible pavement could be increased if commercial vehicles were spread out more across the lane. This could be done by having wider traffic lanes or by re-marking traffic lanes. To test this hypothesis, an experiment, involving accelerated trafficking, was set up at the Transport Research Laboratory (TRL). After experiments were conducted on a test pavement, it was found that the maximum benefit to a pavement was likely to occur when trafficking was used instead of a normal strengthening treatment such as overlay or reconstruction. The technique is suitable for all dual carriageways. Preparations are now being made to validate these findings on trial sites on the road network.