Interventions to reduce the speed of cyclists in work zones—cyclists' evaluation in a controlled environment

Abstract

Current guidelines for work zones do not consider the needs of cyclists and pedestrians enough, which leads to unpredictable situations and a resulting higher crash risk for these road user groups. With respect to motor vehicles, speed management with various interventions is an important and well-studied measure. Their design can be hazardous for cyclists, but a systematic investigation of speed reducing interventions that are applicable to cyclists is lacking. In a controlled setting, four different types of interventions were studied regarding their effect on cyclist speed, attention, and comfort at the first encounter with the intervention and when familiar with the setup. Thirty cyclists with a variety of bicycles first rode a baseline condition to establish their desired speed, then they encountered the interventions eight times in a row. During the first encounter their speed dropped but went back to baseline levels during the following trials, regardless of intervention type. The glance behaviour showed that cyclists' attention was focused much more on the interventions themselves than beyond, which can be problematic in unpredictable environments like work zones. Comfort ratings varied widely, with interventions causing vibrations being rated as least comfortable. To conclude, speed-reducing interventions for cyclists must be applied with care and their effect weighted against potential risks of causing crashes and distraction.