The Mountain Road Hedge Lane Length Study

Emergency escape ramp, one of the most efficiency methods to improve the safety in the long and large longitudinal slope section of highway, has been well know by the engineer and widely used in highway design.The length of emergency escape ramp is the most important factor in its design. The enough of an emergency escape ramp is the only way to afford the maximum safety for the vehicle out of control. In this paper, through series of mechanical analysis for the vehicle running on the emergency escape ramp, we get the formulas to calculate the length of emergency escape ramp. At the same time, the location requirement and design factors (escape ramp type, grade, design speed, pavement type) of emergency escape ramp were deeply analysised. Combine with the safety, stability of the vehicles out of control, we recommend the emergency escape ramp length in different situation.