A geometry elements based speed prediction model for interchange ramps of mountainous motorways

Abstract

The geometric design of motorways in the mountainous area is the top priority of the interchange planning and design. Reasonable ramp geometric design can not only reduce the cost and difficulties of construction of the interchange, but also improve the driving conditions, ensure traffic safety and improve the comfort of driving. Based on the development of foreign geometric alignment design practice, this paper analyze the continuous travel performance of vehicles on mountainous interchange ramps, and then proposes a highway geometric elements design method based on operating speed for practitioners to predict operating speed on ramps. The method will allow the auditors and the designers to proceed operating speed prediction for varied vehicle types for mountainous interchange ramps, which is also expected to give the auditors a good way to evaluate the consistency between driver's expectation and the geometric design of the ramps.