Theory of Breakdown Phenomenon at Highway Bottlenecks

Abstract

On the basis of an empirical study of congestion occurring at a freeway bottleneck, it is shown that the congested regime can exist under a large variation of the discharge flow rate downstream of the bottleneck. This variation can be from about 1,600 to 1,700 vehicles/h to 2,600 to 2,700 vehicles/h per lane. A criticism of the application of queuing theories for the description of traffic pattern features is given. An explanation is given of the features of a congested regime on the basis of the recently discovered properties of synchronized flow as a new traffic phase.