Traffic wave

About: Traffic wave is a research topic. Over the lifetime, 2106 publications have been published within this topic receiving 62117 citations. The topic is also known as: phantom traffic jam & ghost jams.

Acceleration noise in a congested signalized environment. in vehicular traffic science

Abstract: Acceleration noise was measured in several mid-city traffic areas in Manhattan, New York City. The experiments included travel on avenues, with and without progressive signalization, and on congested cross streets that intersect these avenues. It is shown that the signalization often is a more important contributor to acceleration noise than is the volume of traffic. In particular, streets without progressive signalization show little variation in acceleration noise with variation in volume; streets with progression have great variation with volume. Further, subjective observations suggest the conclusion that acceleration noise is not a very good measure of orderliness or smoothness of flow in signalized environments where traffic moves at a low average speed. An alternative measure of acceleration irregularity is proposed to compensate for the difficulties encountered.

Strategy of Traffic Gridlock Control for Urban Road Network

Abstract: In order to relieve traffic congestion and to prevent urban traffic gridlock appearing in oversaturated signalized road network in urban central business district(CBD),defining the accumulated vehicular number in road network of congestion area partitioned from urban road network as traffic state variable,the state-space equation of describing the evolution of macroscopic traffic flow on road network of congestion area was developed.According to Pontryagin minimum principle,the equation was solved and the optimal control strategy was Bang-Bang control,so that the accumulated vehicular number in road network of congestion area reached optimal value.It keeps the maximal capacity of congested road network in minimal time.The control strategy was tested in a congestion road network in core area of Guangzhou.The results show that the strategy can not only prevent oversaturated traffic and gridlock but also benefit the vehicles to enter and leave the road network of congestion area with Pareto improvement.

Microscopic Simulation Research on Signal Cycle Length of Mixed Traffic Considering Violation

Abstract: Mixed traffic is often mistakenly considered as the cause of poor traffic safety and low efficiency. Traditionally, traffic management department would extend the signal cycle length to decrease the start loss caused by frequent starts, and to satisfy the traffic demand of motor vehicles, without considering the demand of pedestrian and non-motorized vehicles. Simultaneously, calculation methods of signal cycle length commonly used currently focus on the balance between delay and capacity, with litter analysis for pedestrians and non-motorized vehicles. On the basis of the typical characteristic of mixed traffic, the calculation of cycle length should take the demand of pedestrians and non-motorized vehicles seriously. Traffic simulation software-VISSIM can be utilized to simulate the state of mixed traffic with the result of the optimized signal cycle length, 110s for the typical intersection. In according with typical mixed traffic intersections, the paper applies the survey data of pedestrians from three signalized intersections in Shanghai and non-motorized vehicles from another three signalized intersections, and establishes the survival curves of pedestrians and non-motorized vehicles with the Survival Analysis Model. Then based on the VISSIM simulation model, the paper studies the relationship among cycle length, average delay and capacity of all the traffic participants under different signal cycle length.

Wave properties of a traffic flow model on highway with ramps

Abstract: In this paper, we use the model is recently presented by us to study the wave properties of the traffic flow on highway with ramps. The results show that the model can perfectly reproduce the effects that ramps have on the formation, the propagation and the evolution of the traffic waves on the main road. Finally, we study the propagating velocity of the first-order wave on the main road and we can further prove that ramps might destroy the stability of the main road traffic flow.