Safety assessment of the interaction between an automated vehicle and a cyclist

Abstract

The operation of automated vehicles in shared areas requires attention with respect to the interaction between AVs and vulnerable road users, including cyclists. Currently, the programmed interaction behavior of AVs is based on the knowledge of the interaction between conventional vehicles and cyclists. However, cyclists may react differently to conventional and automated vehicles. Therefore, this research applies field test experiment to investigate the risks resulting from the interaction between cyclist and an AV. Four possible interaction scenarios were investigated in within-subject design with overtaking speed, overtaking distance and right-hand side objects as attributes. Objective Risk is assessed using the Probabilistic Driving Risk Field and Subjective Risk is assessed based on the self-reported values, cyclist behavior and trust. Results show that in general following has less risk than overtaking. Automated following and manual following have the same level of Objective and Subjective risks, while the automated overtaking has higher risks than manual overtaking. However, results also show that a larger interaction time leads to an increase in cycling speed and decrease in the distance to the curb. Furthermore, in the following maneuver the interaction time is higher than in the overtaking maneuver. Besides high time of interaction, closer overtaking distance and green grass on the right-hand side affect the increase in subjective and objective risks.