Effects of hands-free cellular phone conversational cognitive tasks on driving stability based on driving simulation experiment

• Published in: Transportation research. Part F, Traffic psychology and behaviour Vol. 58; pp. 264 - 281
• Main Authors: Yan, Wei, Xiang, Wang, Wong, S.C., Yan, Xuedong, Li, Y.C., Hao, Wei
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.10.2018; Elsevier Science Ltd
• Subjects: Brakes; Car following; Cell phones; Cellular telephones; Cognitive tasks; Communication; Computer simulation; Crashes; Driving; Driving performance stability; Driving simulator; Emergency response; Emergency vehicles; Hands-free cellular phone conversational cognitive task; Impact analysis; Mathematical calculation; Mathematical models; Railroad accidents & safety; Reaction time; Road safety; Stability analysis; Studies; Variation; Mathematical calculation; Driving simulator; Road safety; Hands-free cellular phone conversational cognitive task; Driving performance stability
• ISSN: 1369-8478; 1873-5517
• DOI: 10.1016/j.trf.2018.06.023

•This seven-level calculation-task baseline was applied.•Normal conversation on a hands-free cellular phone impaired driving performance.•The degree of impairment by normal calculation was caculated.•The complexity of the calculation task was associated with reaction time. Driver distraction due to cellular phone usage is a major contributing factor to road crashes. This study compares the effects of conversational cognitive tasks using hands-free cellular phone on driving performance under three distraction conditions: (1) no distraction (no cellular conversation), (2) normal conversation (non-emotional cellular conversation), and (3) seven-level mathematical calculations. A car-following scenario was implemented using a driving simulator. Thirty young drivers with an average age of 24.1 years maintained a constant speed and distance between the subject vehicle and a leading vehicle on the driving simulator, and then respond to the leading vehicle’s emergency stop. The driving performances were assessed by collecting and statistically analyzing several variables of maneuver stability: the drivers’ brake reaction times, driving speed fluctuation, car-following distance undulation, and car-following time-headway undulation. The results revealed that normal conversation on a hands-free cellular phone impaired driving performance. The degree of impairment caused by normal calculation was equivalent to the distraction caused by Level 3 mathematical calculations according to the seven-level calculation baseline. The calculation difficulty of Level 3 is one double-digit figure plus a single-digit figure, and non-carry addition mental arithmetic is required, e.g., 44 + 4. The results indicated that an increase in the level of complexity of the calculation task was associated with an increase in brake reaction time. The seven-level calculation-task baseline could be applied to measure additional distraction effects on driving performance for further comparison.