01697489

Component

In conditionally automated driving, due to the possible system limits, the driver is required to take-over the vehicle control if a so-called take-over request is issued. This study investigates the effect of scenarios and secondary tasks on the take-over performance and safety. The experiment was conducted in a real vehicle based driving simulator. The manual driving, the 1-back cognitive secondary task and the letter game task were tested. Participants experienced three different traffic scenarios, including a non-critical scenario and two critical scenarios. Results indicated the scenarios and secondary tasks impacts taking-over characteristics; at the meanwhile, a strong influence of the take-over time and driver's workload on the take-over safety. Specifically, the steering reaction was generally slower than the braking reaction, indicating that the lateral operation requires more cognitive and decision-making time. In extreme cases, the braking operation is not sufficient to ensure safety and the steering operation must be taken into account. When obstacles are not easy to detect, or when the driver is engaged in a visual secondary task, the steering reaction time increases significantly. This study can provide data support for take-over safety evaluation of conditionally automated driving.

This paper was sponsored by TRB committee AHB30 Standing Committee on Vehicle-Highway Automation.

19-03360

English

6p

2019

Transportation Research Board 98th Annual Meeting

Digital/other

Figures; References (13) ; Tables

Autonomous land vehicles; Behavior; Drivers; Level 2 driving automation; Level 3 driving automation; Reaction time; Task analysis; Workload

Highways; Safety and Human Factors; Vehicles and Equipment

Transportation Research Board Annual Meeting 2019 Paper #19-03360

TRIS, TRB, ATRI

Dec 7 2018 9:29AM