A smaller radius creates a sharper curve, which results in greater potential for driver error. The central angle decreases as the curve becomes tighter or sharper. This exerts additional forces on drivers, making it more difficult for them to maneuver. The decreased central angle may also reduce the sight distance of a curve. Because of these factors, there is a greater likelihood of accidents.
Accidents are less likely on curves with a high degree of curvature.
Often, a series of high degree curves are located near each other. Their proximity has the effect of slowing drivers. In addition, these sharp curves are often signed well, warning drivers of an approaching hazard. As the length of a curve increases, drivers are required to maintain a proper tracking path for longer periods. Tracking can be affected by drivers misjudging the length of the curve and steering as if the vehicle were in a tangent section.