A quantitative model of takeover request time budget for conditionally automated driving
URL: http://arxiv.org/abs/2408.15682v1
archive: archived pipeline: cataloged verified
Abstract
In conditional automation, the automated driving system assumes full control and only issues a takeover request to a human driver to resume driving in critical situations. Previous studies have concluded that the time budget required by drivers to resume driving after a takeover request varies with situations and different takeover variables. However, no comprehensive generalized approaches for estimating in advance the time budget required by drivers to takeover have been provided. In this contribution, fixed (7 s) and variable time budgets (6 s, 5 s, and 4 s) with and without visual imagery assistance were investigated for suitability in three takeover scenarios using performance measures such as average lateral displacement. The results indicate that 7 s is suitable for two of the studied scenarios based on their characteristics. Using the obtained results and known relations between takeover variables, a mathematical formula for estimating takeover request time budget is proposed. The proposed formula integrates individual stimulus response time, driving experience, scenario specific requirements and allows increased safety for takeover maneuvers. Furthermore, the visual imagery resulted in increased takeover time which invariably increases the time budget. Thus the time demand of the visualized information if applicable (such as visual imagery) should be included in the time budget.
Summary
IEEE Access study of takeover-request time-budget design for conditionally automated driving. Tested fixed (7 s) and variable (6, 5, 4 s) time budgets with and without visual imagery assistance across three takeover scenarios using lateral-displacement and other performance measures. Found 7 s suitable for two scenarios but not all, and proposes a generalized mathematical formula for time-budget estimation that integrates individual stimulus-response time, driving experience, and scenario-specific requirements. Notes visual imagery itself extended takeover time and must be accounted for in the budget.
Key finding
A scenario-aware time-budget formula combining individual response time, experience, and scenario demand outperforms a fixed 7 s budget for conditional-automation takeovers.
Methodology
Driving-simulator factorial study of fixed vs variable takeover time budgets x visual-imagery aid across three scenarios; lateral-displacement-based performance assessment.
Quality score: 5 / 5