Application of the speed prediction model (V85) (V85) in the design of freeway interchanges

Abstract

The design of freeway interchanges is performed on the basis of technical and economic comparison of options for a large number of indicators. Design decisions depend on a large number of factors: the class of intersecting streets and roads, the level of service, traffic intensity, the estimated speed at the ramps, terrain, urban development, hydrogeological conditions of construction, etc. An integral indicator of the quality of design decisions is the maximum safe speed. In most countries of the world, the speed of single passenger cars is 85 % of the security (V85), which may differ from the calculated speed at the maximum safe speed. In the article, on the basis of experimental data, empirical models for calculating speeds (V85) are obtained at freeway interchanges with directional ramps. Experimental studies were performed at freeway interchanges in the city of Moscow using a car laboratory according to the method of following the leader, as well as by processing video from a quadrocopter. The results of the study make it possible to predict the speed of movement (V85) at the ramps of freeway interchange and to compare the freeway interchanges schemes according to the criterion of speed, loss of time, relative safety and traffic capacity.