A model for estimating road wear on in-service roads

Abstract

This article presents a new approach to estimating road wear, where the observation units are in-service roads of the Norwegian national road network, operating under normal traffic conditions. Since the early 1990s, Norway has deployed automatic traffic control units along its national roads. These units can, by a simple modification, be used as weigh-in-motion devices. This makes collecting axle load data from a relatively large number of observation sites cost effective. The new data from weighing vehicles in motion, and from the regular monitoring of the road surface, enable a new approach to modelling road wear developments. A first rutting model is developed based on these data, and the results obtained from it, suggest that Norwegian national roads may be so solid that there is no significant marginal impact from heavy axle loads. Total annual marginal road wear costs based on these estimates appear to be significantly lower than anticipated.

Keywords:

• In-service roads
• Road wear
• Rutting
• Weigh-in-motion

Acknowledgements

The author appreciates comments received on this paper from four anonymous referees. I am also grateful for the valuable comments on an early draft given by Professor Les Foulds. All remaining errors are the author's alone.