California freeway travelers suffer large and variable congestion delay. The delay is due to operational inefficiency, excess demand, and unforseen events. Operational inefficiency reduces speed and may cause queue spillovers that reduce exiting flows. Excess demand creates delay on ramps. Unforseen events such as accidents temporarily reduce capacity. The Cell Transmission Model of a freeway w...

This article presents a study on freeway networks instrumented with coordinated ramp metering and the ability of such control systems to produce arbitrarily complex congestion patterns within the dynamical limits of the traffic system. The developed method is used to evaluate the potential for an adversary with access to control infrastructure to enact high-level attacks on the underlying freew...

A System-Wide Adaptive Ramp Metering (SWARM) system is being implemented in the Portland metropolitan area, replacing the previous pre-timed ramp-metering system. SWARM has been deployed on six major corridors and operates during the morning and afternoon peak hours. This study entails a ―before‖ and ―after‖ evaluation of the benefit of the new SWARM system as compared to the pre-timed system u...

Highway management systems are used to improve safety and driving comfort on highways by using control strategies and providing information and warnings to drivers. They use several strategies starting from speed and lane management, through incident detection and warning systems, ramp metering, weather information up to, for example, informing drivers about alternative roads. This paper provid...

This paper describes the evaluation approach that will be used to assess the performance of the Ramp Metering Control (RMC) for the New Jersey Department of Transportation in the United States. The primary objectives of the evaluation are to assess the impact of RMC control strategies on traffic flow and support the analysis of critical operational procedures. The framework for the evaluation c...