  Spatiotemporal features and physics of vehicular traffic congestion occurring
due to heavy freeway bottlenecks caused by bad weather conditions or accidents
are found based on simulations in the framework of three-phase traffic theory.
A model of a heavy bottleneck is presented. Under a continuous non-limited
increase in bottleneck strength, i.e., when the average flow rate within a
congested pattern allowed by the heavy bottleneck decreases continuously up to
zero, the evolution of the traffic phases in congested traffic, synchronized
flow and wide moving jams, is studied.
