Truck lane restriction
Truck lane restriction within transportation traffic engineering, is a factor impacting freeway truck lanes and traffic congestion. In traffic flow theory, intuitively, slow vehicles (e.g. trucks) will cause queues behind them, but how it relates to the kinematic wave theory was not revealed until Newell. Leclercq et al did a complete review of Newell's theory. In addition to the simulation models developed by Laval and Daganzo on the basis of numerical solution methods for Newell's theory to capture the impacts of slow vehicle, Laval also mathematically derived the analytical capacity formulas for bottlenecks caused by single-type of trucks for multi-lane freeway segments. Analytical Solution of the Single-type Truck Problem Laval's solution could be summarized as follows: Assuming a one-lane freeway segment obeying the triangular fundamental diagram defined in the figure to the right with free-flow speed u, wave velocity w and jam density kj. Only one truck type is considered. In this scenario, the normalized capacity I of the freeway segment is given as： where r is the time-mean proportion of trucks in the traffic stream,C = uwnkj/(w+u)is the capacity of the freeway lane without trucks and H is the expected value of headway between two consecutive trucks at the