Rut Formation and Rolling Resistance on Earth Roads

The importance of rural transport services in developing countries and the effects of vehicle-road interactions on total cost are outlined. Previous work on relationships between soil characteristics, tyres sizes, sinkage and rolling resistance is reviewed. An experiment using a range of typical transport vehicle tyre sizes to measure rut depth and area in a soil bin is described. The results are compared with corresponding relationships derived from some of the earlier work and it is concluded that a strong relationship exists between mobility number and tyre sinkage, which is largely independent of tyre size. An investigation into the potential for a reduction in rutting through the use of various geotextiles is also described. An application of the work to further research in the field is briefly outlined.