Why drivers rush into "safe-looking" short tunnels: the misleading effect of spatially intervisible.

OBJECTIVE

The access zone of short tunnels exhibits an abnormally high accident rate, yet the underlying environmental causes remain unclear. This study identifies the key environmental feature behind this safety paradox and explains how it induces abnormal speed control.

METHODS

We collected eye movement, driving performance, and video data from 30 drivers in 18 tunnel approach zones using a combined field and subjective approach. Subjective perception experiments identified "spatial intervisibility", the ability to see through the tunnel from the approach, as the critical feature. We compared two nearly identical tunnels differing only in intervisibility and applied Task Analysis of Driving Scenarios (TADS) to track behavioral evolution.

RESULTS

Subjective results showed 77% of drivers perceived the intervisible short tunnel as most distinct. Objectively, despite similar recognition of speed‑limit signs, drivers in intervisible tunnels delayed deceleration onset by 41%, began slowing at a 6% higher speed, and reached the portal 6% faster. Speed compliance plummeted from 70% to 17%. Eye‑tracking revealed the mechanism: the see‑through tunnel increased fixations on itself by 26%, reducing attention to surroundings.

CONCLUSIONS

The misleadingly open vista causes visual guidance failure, inducing delayed deceleration and speed violations that elevate collision risk. These findings directly support targeted interventions such as dynamic speed guidance for such tunnels.