Advanced continuum traffic flow models for congested freeways

Advanced traffic management, simulation, and control schemes require reasonably accurate descriptions of flow dynamics especially at congested conditions. Two new high-order continuum traffic flow formulations are developed for treating congested flows and complex geomctrics such as entrance and exit ramps. The acceleration and inertia effects of the traffic mass are properly addressed in the new formulations. Traffic friction due to lane changing at freeway/ramp junctions is also treated through the use of a friction term in the first formulation and a viscosity term in the second. The new models do not require the use of an equilibrium speed-density relationship, and thus they require less calibration effort in field applications. Satisfactory results are obtained when the models are tested in situations involving pipeline freeways, entrance ramps, and exit ramps. Field data from both loop detectors and video detectors are used. These tests suggest that the new models are capable of describing traffic dynamics at various traffic conditions and changing geometrics.