In previous studies of barrier separated road types, it was found that vehicle lane position and the amount of lateral wander varied depending on road type and lane width. These variations will have a direct effect on the rate of surface wear and will influence where stresses and strains are distributed in the pavement structure. In order to determine the extent of these variations, a series of position surveys were carried out on common road types found on the Swedish road network. Twenty-one sets of survey data provided information on over 271,000 vehicles. The data was divided into three groups depending on approximate axle track width. Using the survey data, it was possible to calculate and plot the distribution of lateral position (wheel path), the average position, and the variation of lateral position (lateral wander) for each group. Factors such as lane type, lane width, verge width, total width, and close proximity of guardrail all had some influence on vehicle position and amount of lateral wander. The extent of lateral wander varied quite considerably. Standard deviation values associated with the average position of light vehicles varied between 455 millimetres and 190 millimetres. Commercial traffic values were lower and ranged between 430 millimetres and 140 millimetres. These are large variations and will have a significant effect on road degradation rates. Such variations should be taken into account when planning construction or maintenance work. (Author/publisher)
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