Study on Longitudinal Gradient at Mountain Highways Based on Driver´s Physiological Reactions

This paper studies the relationships of various vertical grades at longer slope mountainous terrain highways on the driver´s heart rate. This paper analyzes the vertical grade effects by measuring the driver´s heart rate and the vehicle speed using the auto-recording heart rate instrument and motive GPS respectively. The research results suggest that the profile grade at the long slope alignment should not be more than 5% for mountain highways and signing improvements, which may reduce accidents in such terrains.