Is drivers’ interaction with pedestrians affected by cognitive load and LED bands? A driving simulator study investigating performance across two age groups during different ambient lighting conditions

Abstract

Pedestrians, being vulnerable road users, are disproportionately affected by road traffic crashes. Many factors influence driver-pedestrian interactions and hence pedestrian safety. Within these interactions, drivers play a critical role as operators of the vehicle. Therefore, it is crucial to understand what factors influence drivers’ perceptions and actions when interacting with pedestrians in different situations. A driving simulator study was designed to investigate the effects of age (younger and older drivers), cognitive load (no task, 2-back task), the presence (or absence) of a zebra crossing, ambient lighting (daylight, after dark), pedestrian position (standing, walking), and whether the pedestrian was wearing a light-emitting diode (LED) band on drivers’ yielding behaviours during interactions with pedestrians. Two groups of drivers (23 younger drivers: Mdn_age = 22 and 19 older drivers: Mdn_age = 64) completed two experimental drives during daylight and after dark. Objective measures (probability of yielding and average deceleration) were used to interpret yielding behaviour and the factors influencing it. The results showed that drivers were more likely to yield when a zebra crossing was present. For conditions with zebra crossings, drivers were more likely to give way to pedestrians waiting by the crossing than when pedestrians were approaching the crossing. Drivers of both age groups behaved in a similar way with standing pedestrians. But with walking pedestrians, younger drivers were more likely to yield and did so softer. In trials where the pedestrians wore LED bands to enhance their conspicuity, the average deceleration was reduced, resulting in smoother braking. These results inform the development of policy and interventions (e.g., effectiveness of zebra crossings, effects of LED bands) to improve the safety of vulnerable road users.