The effect of curve geometry on driver behaviour in curves by using naturalistic driving data

Traffic accidents are commonly found on horizontal curves. It is therefore important to study how the curve geometry affects the driver behaviour. This paper focuses on analysis of speed and maximal lateral acceleration in seven curves on two-lane rural highways in Sweden. The curve geometry factors studied are radii, presence and length of spiral transitions, tangent lengths and radius of previous curve. Of the studied factors, radii and spiral transitions were found to influence the driver behaviour most. Both larger radii and longer spiral transitions result in higher speeds in curves, and speed variations within curves seemed to be independent on choice of speed entering the curve.