Effect of strength and direction of haptic cueing on steering control during near lane departure

21 The present study compared two distinct approaches to designing driving assistance devices. 22 These devices aim to facilitate steering responses by delivering directional pulses on the 23 steering wheel when lane departure is imminent. In one case, the aim is to prime the 24 corrective gesture through a haptic cue in the direction of the lane centre (motor priming). The 25 other approach consists of eliciting a compensatory reflex reaction by means of a jerk of the 26 steering wheel in the opposite direction. Central to this investigation are the safety benefits of 27 the devices and the ability of drivers to remain in full control of their steering responses. The 28 steering behaviour of 18 participants during near lane departure in bends and in straight lines 29 was analysed. The strength and direction of haptic cueing was manipulated. The results show 30 that drivers were always able to control the direction of the steering response when the haptic 31 cue was delivered. No reflex counteraction was observed, whatever the strength or the 32 direction of the stimulus. The fastest responses were observed when the cue was directed 33 toward lane departure, especially when cueing was strong. However, these did not necessarily 34 lead to the fastest returns to a safe position in the lane when compared with motor priming 35 toward the lane centre. The latter yielded improved manoeuvre execution as soon as the 36 steering movement was initiated. These results are discussed in relation to the sensorimotor 37 and cognitive processes involved in steering behaviour. Their implications for the design of 38 haptic-based lane departure warning systems are considered. 39 40