Navigation errors (missed, wrong, and risky turns) reflect cognitive failures that remain insufficiently understood in in-vehicle navigation. This thesis examines how level of map guidance detail and cognitive distraction shape these errors through the lens of situation awareness. In a 2×2 within-subjects simulator study (N=40), drivers completed four urban routes under Road-level versus Lane-level Navigation (LLN) guidance, with and without an auditory 2-back task. Multimodal data were collected, including vehicle control, eye movements, secondary task performance, and subjective workload and user experience ratings. Observed navigation errors were mapped to perception, interpretation, or decision-making failures in cognitive processes.
LLN significantly reduced interpretation failures and wrong turns, contributing to a 40% reduction in total errors. It also reallocated attention toward the navigation display, as shown by more frequent and longer glances and broader scanning, without degrading vehicle control. Distraction robustly elevated workload and reduced road monitoring, but session-level error rates remained unchanged. Interaction analyses showed that distraction attenuated LLN’s attention-shift effects, while LLN mitigated some distraction costs in road monitoring; certain control benefits, however, reversed under load. Driver experience moderated outcomes: experienced drivers benefited consistently from LLN, with fewer errors and lower workload, while less experienced drivers reported higher workload and a tendency toward more missed turns.
Together, these findings demonstrate how navigation errors can be systematically mapped to underlying cognitive failures and reveal how level of map guidance detail and distraction influence these processes, providing a foundation for more context-aware navigation support.