Abstract:
Traffic breakdown is the main cause of vehicle traffic congestion in multi-lane
roads due to highway bottlenecks such as lane-drops, on and off-ramps. In this
study, the nature of traffic congestion and phase transition at the highway
bottlenecks is explained. A multi-lane macroscopic traffic flow model of
Aw-Rascle type is derived from the kinetic traffic flow model in which the
lane-change terms are expressed explicitly. This is achieved by first developing
the Kinetic traffic flow interaction operators and then applying the method of
moments to get the corresponding macroscopic equations. For simulation of the
traffic congestion, we consider a highway with three traffic lanes that have
stationary bottlenecks. The macroscopic model equations for each lane are
solved numerically using finite volume method (Godunov scheme), whereby the
Euler’s method is used for the source term. The results of the simulations of the
congestion near and within the bottlenecks are presented in form of graphs and
space-time plots. These results show that vehicle lane-change manoeuvre near
the bottlenecks lead to traffic breakdown and congestion on the lane adjacent to
the bottlenecks compared to the other express lanes in the highway. This
prompts the following vehicles moving in the outermost lane to either slow
down upon reaching the disturbance region or change to the other lanes before
they reach the merging region. The model results provide important insight into
improving the road network design and safety management strategies especially
when new roads are constructed.
