Driver Takeover Performance under Different Driving Contexts and Non-Driving Tasks in Level 3 Automated Driving

In Level 3 (L3) automated driving, drivers may disengage from continuous control but must resume control when a takeover request (TOR) occurs. Drivers’ takeover readiness may be reduced by engagement in non-driving-related tasks (NDRTs), especially in more complex urban environments. However, limited evidence is available on how driving context and NDRT demand jointly affect takeover performance in L3 automation.

To address this gap, we conducted a driving-simulator study with 18 licensed drivers using a 2 × 3 within-subject design that combined two driving contexts (highway and urban) and three NDRTs (music listening, entertainment video viewing, and news summarization). Takeover performance was evaluated using takeover reaction time (TRT), eye-tracking measures, heart rate variability (HRV), and subjective ratings of workload and situational awareness. Both driving context and NDRT demand affected takeover performance.

Urban scenarios were associated with longer TRT, higher workload, and more dispersed visual attention than highway scenarios. Increasing NDRT demand was associated with poorer takeover performance, and news summarization produced the longest delays, greater off-road attention, slower gaze return after TOR, and reduced situational awareness. HRV measures further indicated higher physiological stress under high-demand NDRTs, particularly in urban conditions.

These findings highlight the need for context-aware takeover support that accounts for both environmental complexity and NDRT demand.