Abstract
The approach used in assessing the justification for providing climbing lanes over the pennines on both the Yorkshire and Lancashire sides is outlined. Since normal speed /flow relationships do not take account of the interaction between very slow and faster traffic, surveys were undertaken to examine vehicle speeds. These determined heavy and light vehicle speeds both instantaneously and over the whole gradient. From these and direct observations, some interesting conclusions are drawn on heavy and light vehicle behaviour and the circumstances in which motorway climbing lanes may have merit.