The level of service on a freeway network is determined by traffic flow on freeway sections with low capacity. These bottlenecks usually consist of sections in which there is some form of discontinuity such as a ramp, a weaving section or a lane drop. For estimation of the capacity near a discontinuity, engineers in The Netherlands use guidelines for freeway design that are in large part based on the Highway Capacity Manual (HCM). In most cases the capacity predicted by the HCM is different from empirical data collected on several sites on the freeway network in the Netherlands. At the Transportation Research Laboratory (TRL) of the faculty of Civil Engineering at Delft University of Technology, a study has Technology, a study has been done on the traffic operation near discontinuities. In this paper, three types of discontinuities will be discussed: two types of weaving sections (2+1 and 3+1 lanes) and a single lane on-ramp on a 6-lane freeway. To evaluate the capacity, a microscopic simulation model called FOSIM has been used. (A)
Abstract