Highways Agency Reports

A procedure is described for estimating the damaging power of road traffic. Each vehicle in the traffic stream is observed and counted, classifying the counts by type of vehicle and by its apparent degree of lading under the broad headings of 'empty', 'fully laden' and 'part laden'. During trials, it is found that the cumulative damaging power can be estimated to within 55% of its true value. With experience, this error can be reduced to +/- 20%. The procedure uses fixed damage factors characteristic of each type of vehicle in the 3 states of lading, which are independent of location or traffic flow. The report describes how these have been calculated from first principles using data readily available from manufacturres.