Bendiness

Curves are considered to be a risk factor in the design of roads. Most research on the risk of curves focuses on individual curves, only a few studies focus on bendiness. Findings from those studies are inconsistent. Two studies on bendiness report a higher risk of crashes on roads with a higher degree of bendiness and two studies found no relation, while three more recent studies report a lower risk on crashes with a higher level of bendiness. Studies reporting lower crash numbers on roads with higher bendiness hypothesise that this might be due to a better anticipation of drivers on curves. Checks are missing however whether the degree of bendiness/number of curves is related to the amount of traffic or to safety measures on more dangerous curves. Based on these findings the verdict on the effects off bendiness on crashes is therefore inconclusive. On the basis of these results, there is also no clear expectation concerning the effects of the measure of reducing the number of curves.