An Analysis of Vulnerable Road Users Overtaking Maneuver along the Urban Road

Abstract

This paper discusses driving styles while overtaking a vulnerable road user who moves along the shoulder in urban roads. Based on the data obtained from an experiment in pre-defined conditions (combinations of four main effects: vehicle’s initial speed, lane width of the road, vulnerable road users’ type, and location in the shoulder) with an immersive driving simulator, we analyzed four different driving styles of drivers while approaching and passing the objects. It is shown that drivers took avoidance maneuvers even if there was no clear risk of collision to vulnerable road users. The results showed that the drivers tended to have a unique perception about the lateral passing gap and overtaking strategy with two worth notice groups: overcaution drivers and reckless drivers. The road characteristic has a statistically significant effect for all types of drivers. Moreover, the effect of the vehicle’s initial speed on overtaking strategy and the effect of vulnerable road user location on minimum lateral passing gap are statistically significant. The findings provide some implications for the development of automotive safety systems that can reduce the risk of overtaking maneuvers in urban areas.

Proposal of Risk Estimation Index from Driver Behaviour for Approaching and Overtaking Vulnerable Road User

“…Researchers (3,9,23) have suggested that when approaching a VRU moving on the shoulder, two strategies can be considered to regulate the vehicle's velocity: flying overtaking (i.e., maintaining or increasing the initial speed) and accelerative overtaking (i.e., decreasing the speed to consider the situation before accelerating to overtake a VRU). Moreover, drivers notice the existence of a VRU and avoid him/her when overtaking (i.e., moving away in the horizontal direction) (3,9) .…”

“…In this study, four driving styles of drivers in a normal state were investigated using experimental from an immersive driving simulator (9) (Fig. 7).…”

“…Vehicle-VRU interactions have been investigated extensively in recent studies (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13) . The ADAS uses automated technology to detect nearby obstacles or driver errors and then provides the appropriate response.…”

“…Despite the effective performance, such systems may be turned off by the driver. Analyses show the trend of VRU avoidance: although drivers can decelerate the vehicle, they prefer to steer away to maintain a large gap when passing VRUs in most situations (2)(3)(4)(5)(6)9) . It is believed that if the individual driving style can be reflected by a vehicle's movement, then a driver's mutual acceptance can be achieved to promote the utilization of ADASs and AVs (14)(15)(16) .…”

“…In our previous study (3,9) , we investigated the different driving styles in approaching and overtaking a VRU based on the lateral gap between a vehicle and a VRU, changes in velocity, and the TTC at the start of braking and steering. We assumed that, in normal driving, each driver has its own limit level of situational risk.…”