논문 상세보기
pp.105-118
PURPOSES : This study aims to evaluate the road safety of the super-elevation transition section of a left turn curve and suggest the minimum longitudinal grade of a super-elevation transition section to be used before and after a left curved section.
METHODS: We evaluated the road condition by means of the safety-criterion-evaluation method involving side friction factors, and then solve the problem by introducing the minimum longitudinal grade criterion based on conditions described in the hydraulics literature.
RESULTS : It was calculated that when a road satisfies hydroplaning conditions, the difference between side friction assumed and side friction demanded is less than - 0.04. In this case, the safety criterion for the condition is unsatisfied. Conversely, when a road is in a normal state under either wet or dry conditions, it was calculated that the difference between side friction assumed and side friction demanded is more than 0.01. Thus, the safety criterion for this condition is found to be satisfied. After adjusting the minimum longitudinal grade applied to a super-elevation transition section, the hydroplaning condition can be eliminated and the safety criterion can be met for all sections.
CONCLUSIONS : It is suggested that a minimum longitudinal grade should be provided on super-elevation transition sections in order to prevent hydroplaning.
