TY - JOUR

T1 - The influence of time headway on subjective driver states in adaptive cruise control

AU - Siebert, Felix

AU - Oehl, Michael

AU - Pfister, Hans-Rüdiger

PY - 2014/7

Y1 - 2014/7

N2 - There is no agreement on the relation between driving parameters and drivers' subjective states. A linear as well as a threshold relationship for different subjective variables and driving parameters has been put forward. In this study we investigate the relationship between time headway and the ratings of risk, task difficulty, effort, and comfort. Knowledge about this interrelation may advance the development of adaptive cruise control and autonomous driving and can add to the discussion about driver behavior models. An earlier study (Lewis-Evans, De Waard, & Brookhuis, 2010) found a threshold effect for drivers' ratings of subjective variables for time headways between 0.5 and 4.0 s at a speed of 50 km/h. This study aims to replicate the threshold effect and to expand the findings to time headways at different speeds. A new measure for criticality was added as a categorical variable, indicating the controllability of a driving situation to give indications for the appliance of time headway in adaptive cruise control systems. Participants drove 24 short routes in a driving simulator with predefined speed and time headway to a leading vehicle. Time headway was varied eightfold (0.5-4 s in 0.5 s increments) and speed was varied threefold (50, 100, 150 km/h). A threshold effect for the ratings of risk, task difficulty, effort, and comfort was found for all three different speeds. Criticality proved to be a useful variable in assessing the preferred time headway of drivers.

AB - There is no agreement on the relation between driving parameters and drivers' subjective states. A linear as well as a threshold relationship for different subjective variables and driving parameters has been put forward. In this study we investigate the relationship between time headway and the ratings of risk, task difficulty, effort, and comfort. Knowledge about this interrelation may advance the development of adaptive cruise control and autonomous driving and can add to the discussion about driver behavior models. An earlier study (Lewis-Evans, De Waard, & Brookhuis, 2010) found a threshold effect for drivers' ratings of subjective variables for time headways between 0.5 and 4.0 s at a speed of 50 km/h. This study aims to replicate the threshold effect and to expand the findings to time headways at different speeds. A new measure for criticality was added as a categorical variable, indicating the controllability of a driving situation to give indications for the appliance of time headway in adaptive cruise control systems. Participants drove 24 short routes in a driving simulator with predefined speed and time headway to a leading vehicle. Time headway was varied eightfold (0.5-4 s in 0.5 s increments) and speed was varied threefold (50, 100, 150 km/h). A threshold effect for the ratings of risk, task difficulty, effort, and comfort was found for all three different speeds. Criticality proved to be a useful variable in assessing the preferred time headway of drivers.

KW - Business psychology

KW - human

KW - Adaptive cruise control

KW - Criticality

KW - Driver behavior modeling

KW - Time headway

KW - Psychology

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=84901927365&partnerID=8YFLogxK

U2 - 10.1016/j.trf.2014.05.005

DO - 10.1016/j.trf.2014.05.005

M3 - Journal articles

VL - 25

SP - 65

EP - 73

JO - Transportation Research Part F: Traffic Psychology and Behaviour

JF - Transportation Research Part F: Traffic Psychology and Behaviour

SN - 1369-8478

IS - A

ER -