Speed and lateral placement on horizontal curves

This paper describes an in-depth study of the behavior of drivers negotiating horizontal curves before and after realignments. The aim was to identify differences in behavior between individual drivers and changes in behavior consequent to curve realignment. The study involved estimating the speed and path radius, and the consequent side friction demand, for each driver. The results show that the path radius can be very different from the curve radius, due to substantial variations in lateral placement as vehicles approach and traverse the curves.