The objective of research in this field in Britain has been to determine by limited surveys mean spectra for commercial axles appropriate to different classes of road, e.g. industrial motorways and major trunk roads, rural major roads, secondary rural roads and roads in residential areas. Typical spectra obtained in this manner are converted to an equivalent number of standard 8200 kg. (18,000 1b) axles per 100 commercial axles, using the A.A.S.H.O. equivalence factors. In using this approach two other pieces of information are required: (1) the average number of axles per commercial vehicle, and (2) the distribution of commercial traffic between the carriageway lanes. Studies of these two factors have recently been made in Britain and the results are summarized in the paper.
Abstract