Lane Keeping Under Cognitive Load

Objective: A pair of simulated driving experiments studied the effects of cognitive load on drivers’ lane-keeping performance. Background: Cognitive load while driving often reduces the variability of lane position. However, there is no agreement as to whether this effect should be interpreted as a performance loss, consistent with other effects of distraction on driving, or as an anomalous performance gain. Method: Participants in a high-fidelity driving simulator performed a lane-keeping task in lateral wind, with instructions to keep a steady lane position. Under high load conditions, participants performed a concurrent working memory task with auditory stimuli. Cross-spectral analysis measured the relationship between wind force and steering inputs. Results: Cognitive load reduced the variability of lane position and increased the coupling between steering wheel position and crosswind strength. Conclusion: Although cognitive load disrupts driver performance in a variety of ways, it produces a performance gain in lane keeping. This effect appears to reflect drivers’ efforts to protect lateral control against the risk of distraction, at the apparent neglect of other elements of driving performance. Application: Results may inform educational efforts to help drivers understand the risks of distraction and the inadequacies of compensatory driving strategies.