Juan Argote

Arterial Queue Spillback Detection and Signal Control Based on Connected Vehicle Technology

Queue spillbacks are a major problem in urban signalized arterials because such spillbacks can lead to gridlock and excessive delays. Several methods based on fixed-location detector data have been proposed to identify the occurrence of queue spillbacks and implement signal control strategies to mitigate their impacts. This paper presents two queue spillback detection methods based on connected vehicle (CV) or probe data. The first method requires only the use of CV data and is based on the notion that nonequipped vehicles in queue that arrive after the last CV-equipped vehicle can be modeled by using a geometric distribution. The second spillback detection method combines CV data with information about the signal settings at the upstream intersection and is based on a kinematic wave theory of traffic. The authors also developed a signal control strategy to mitigate queue spillbacks once they were detected. The proposed queue spillback detection methods and alternative signal control strategy were tested through simulation on a four-signal segment of San Pablo Avenue in Berkeley, California. The results show the penetration rate thresholds of CV-equipped vehicles required for accurate queue detection. The proposed signal control strategy improved traffic operations for the upstream cross streets without compromising traffic operations on either direction of the arterial traffic and substantially reduced the variation of the queue length on the critical arterial link.

Estimation of measures of effectiveness based on Connected Vehicle data

Vehicle-infrastructure cooperation via the Connected Vehicle initiative is a promising mobile data source for improving real-time traffic management applications such as adaptive signal control. This paper focuses on developing estimation methods with the use of Connected Vehicle data for several measures of effectiveness (e.g., queue length, average speed, number of stops), essential for determining traffic conditions on urban signalized arterials for real-time applications. This research systematically determines minimum penetration rates that allow accurate estimates for a wide range of measures of effectiveness in undersaturated traffic conditions. The estimation of these measures and minimum penetration requirements has been tested using Next Generation Simulation (NGSIM) data.

Policies to Address Conflicts Between Passenger and Freight Rail Service in the U.S.

A renewed interest in expanding passenger service on rail in the US faces challenges and opportunities in that most of the railroads are privately owned. Up to this point railroad network capacity has kept up with demand relatively well. However, signs of strain are apparent looking into the future as freight volumes increase with globalization and conflicts with passenger trains increase with the addition of more intercity and commuter lines. Case studies were conducted to understand the relationship between passenger and freight operations in the US and to identify areas of conflict and opportunities for improvement. Common conflicts arise from differing objectives and include cost sharing, safety, liability and infrastructure needs. Currently, public agencies and railroad companies deal with these conflicts through an outdated regulatory framework that in many cases does not serve the interests of either party; improvements here are possible. Additionally, a greater use of hybrid agreements where government agencies fund capacity improvements for passenger and freight operations simultaneously may offer the best approach for dealing with these conflicts and adapting the rail network to meet demands into the future.Copyright