Traffic Operations and Management

Congestion pricing improves economic efficiency, but it may lead to inequitable outcomes. A key policy priority in California is identifying ways to avoid the hardship of congestion pricing on low income or other vulnerable populations. This study uses data from a congestion pricing experiment in the Seattle metro area to examine the feasibility of using revenue from congestion pricing to compensate those harmed by the policy. Results indicate that the initial burden of congestion pricing is highly inequitable, with the lowest income drivers paying an average of 7 percent of their weekly...

An earlier empirical study of San Francisco Bay Area freeways concluded that HOV lanes unfavorably affect freeway traffic by creating congestion. That study attributed the observed congestion to HOV lanes and tentatively recommended their elimination over the full lengths of the freeways it examined; and even from all Bay Area freeways. It recognized, however, that its analysis is fragmentary and recommended further work to solidify its conclusions. This is logical since the study lacks a spatiotemporal analysis to pinpoint where and how congestion first forms (at bottlenecks).The present...

As demonstrated by the Camp Fire evacuation, communications (city-to-city, city-to-residents) play important roles in coordinating traffic operations and safeguarding region-wide evacuation processes in wildfire events. This collaborative report across multiple domains (fire, communication and traffic), documents a series of simulations and findings of the wildfire evacuation process for resource-strapped towns in Northern California. It consists of: (1) meteorological and vegetation-status dependent fire spread simulation (cellular automata model); (2) agency-level and agency-to-residents...

This paper presents a numerical method to model kinematic wave (KW) traffic streams containing slow vehicles. The slow vehicles are modeled discretely as moving boundaries that can affect the traffic stream. The proposed scheme converges in flows, densities and speeds without oscillations, and therefore can be readily used in situations where one wishes to model the effect of the traffic stream on the bottlenecks too. The approach is more accurate than Godunov's method in situations where the latter can be applied.