Combined horizontal and vertical alignments are frequently used in mountainous freeways in China; however, design guidelines that consider the safety impact of combined alignments are not currently available. This project aims to estimate the effects of combined alignments on driving behavior (e.g., speed and lateral acceleration) and safety performance (crash surrogate measures like lane departure events and emergency braking events) using a driving simulator and field data. The results will assist engineers to design safer mountainous freeways.
- Replicated the full range of combined alignments used on a mountainous freeway in China using Tongji University driving simulator.
- Investigated the effects of combined alignment on lateral acceleration, lane offset, and speed variation.