External Factors Affecting Motorway Capacity

A method for assessing the impact of external factors on motorway capacity is presented. Factors such as precipitation, lighting conditions, merge, diverge and HGV percentages were considered. A univariate analysis of variance shows that different factors are affect capacity between different motorway locations, and that only part of the observed variance in capacity is explained. Suggestions for improvements are made, including the use of higher resolution data and the parameterization of more factors.