Many cities are built around rivers in the world, and the river-crossing
corridors are often their traffic bottlenecks, leading to severe congestions.
Changsha is a city divided into two parts by a river with eight river-crossing
corridors in China. Aiming at this issue, take Changsha as an example, this
study explores developing a precise traffic restriction policy on those
river-crossing corridors. First, an investigation is conducted to collect
traffic flow data of those corridors. It is found that those corridors generally
have serious congestion at peak hours, but their congestion levels vary greatly
by corridor and direction. Then, two Greenberg models are developed for the
4-lane and 6 & 8-lane corridors, respectively, to figure out their traffic
flow features. Third, a precise traffic restriction policy that balances traffic
flows in different corridors is proposed. It would restrict 10% of motor
vehicles on those most congested corridors, and the restricted vehicles are
proportionally diverted to the neighboring non-congested corridors by detour
distances. Finally, based on the estimated Greenberg models, traffic speeds of
those corridors after traffic restrictions are then predicted. It is found that
traffic congestions in those congested corridors are greatly alleviated, and the
average travel speed of all the corridors increases by 2.8 km/h at the AM peak
and 4.5 km/h at the PM peak, respectively.
