Traffic Operations and Management

Attica Tollway Management in the Athens 2004 Olympic Games

Halkias, Bill
Papandreou, Konstantinos
Kopelias, Pantelis
Prevedouros, Panos D
Skabardonis, Alexander
ITS America
2005

Attica Tollway (Attiki Odos Motorway), the peripheral motorway of Athens metropolitan area, is the first road concession project in Greece. Attica Tollway provides safe and uninterrupted traffic flow conditions, saving more 270,000 person hours of delay per day with substantial savings in fuel consumption and air pollutant emissions. During the Athens 2004 Olympic Games, special traffic management plans were successfully implemented to ensure quick and safe access to the Olympic venues and to maintain a high level of service to all tollway users. The paper presents routine and emergency...

Assessment of traffic simulation models : final report

Skabardonis, Alexander
University of California, Berkeley
Washington State Department of Transportation
1999

This report describes a study which focused on the selection and application of traffic simulation models. The models were evaluated for: capabilities and features, input data requirements, output options, relationship with traditional planning and operational analysis tools, and modeling effort and costs.

Assessment of the Impact of Weather on Freeway Operations in California

Seeherman, Joshua Lawrence
Sisiopiku, Virginia
Skabardonis, Alexander
Transportation Research Board
2012

Several factors contribute to traffic congestion on highway facilities including adverse weather conditions. However, the extent of weather impacts on traffic flow and congestion delay on freeways is not fully known. This study analyzed an extensive set of historical traffic data from the state of California to gain a better understanding of the proportion of traffic delay that can be directly attributed to weather. A congestion estimation model was developed to estimate vehicle delays directly attributed to rain on 17 urban freeway corridors. It was found that delay due to rain ranged...

Assessment of the benefits from signal hardware improvements

Skabardonis, A
Deakin, E A
University of California, Berkeley
1995

Signal equipment upgrades (e.g., multiple timing plan capability and/or signal interconnection) are commonly used to improve the quality of traffic flow in urban arterials and networks. These signal control improvements generally result in considerable delay, stops and fuel savings but the benefits vary widely on different networks. Procedures are needed to provide guidance on the benefits likely to be achieved from improving signal hardware. This report discusses the major factors that influence signal equipment performance and presents the findings of the assessment of the impacts from...

Assessment of the Applicability of Bus Rapid Transit on Conventional Highways—Case Study Feasibility Analyses Along the Lincoln Boulevard Corridor

Skabardonis, Alex
Miller, Mark A.
Li, Irene Yue
Cervero, Robert
Murakami, Jin
2009

This report presents the results of a performance assessment of the applicability of bus rapid transit on conventional highways in the setting of a site-specific case study along the Lincoln Boulevard corrider in Santa Monica, California. When bus rapid transit systems are implemented on conventional highways, especially on arterials, there are numerous bus priority treatments that can be applied and each has associated with it issues that need to be investigated. In this study, we are investigating concurrent flow curb bus lanes based on the removal of peak period parking along the...

Assessing the Traffic Impacts of Transportation and Land Development Scenarios

Deakin, E A
Skabardonis, A
Walukas, E
Transportation Studies
1985

This paper demonstrates the use of the transyt model in assessing the traffic impacts of transportation and land development scenarios. Using the downtown area of the city of Berkeley as a case example, the effects of overall traffic growth, project-specific traffic increases, alternative parking policies, tsm programs, and street and intersection design changes are explored. The results show that once transyt is calibrated for an area, it can be applied relatively quickly and inexpensively as a sketch-planning tool. (a) (Author/TRRL)

Arterial traffic signal optimization: A person-based approach

Christofa, Eleni
Ampountolas, Konstantinos
Skabardonis, Alexander
2016

This paper presents a real-time signal control system that optimizes signal settings based on minimization of person delay on arterials. The system’s underlying mixed integer linear program minimizes person delay by explicitly accounting for the passenger occupancy of autos and transit vehicles. This way it can provide signal priority to transit vehicles in an efficient way even when they travel in conflicting directions. Furthermore, it recognizes the importance of schedule adherence for reliable transit operations and accounts for it by assigning an additional weighting factor on transit...

Arterial Traffic Estimation Using Field Detector and Signal Phasing Data

Gan, Qijian
Skabardonis, Alexander
University of California, Berkeley
2019

In this project, a novel approach has been developed to estimate the traffic states on arterial road links controlled by signalized intersections using both loop detector data and signal phasing information. The authors derived a trapezoidal fundamental diagram that includes two occupancy thresholds to categorize the traffic states into three different regimes: uncongested, congested, and downstream queue spillback. The parameters used to compute these two thresholds are closely related to road geometry, detector layout, signal settings, and vehicle dynamics, which can be obtained from the...

Arterial Speed Management with Control Measures: the Case of San Francisco, California

Halkias, Michael
Leng, Thalia
Sorell, Miriam
Parks, Jamie
Skabardonis, Alexander
2017

High vehicle speeds are strongly associated with both a greater likelihood of crash occurrence and more serious pedestrian injury. This study evaluated the effectiveness of traffic signal progression as a speed management tool in three arterial corridors in the city of San Francisco. Analysis of “before” and “after” field data on traffic volumes and speeds were used in the evaluation supplemented with estimates of air pollutant vehicle emissions. The findings show that the implemented control measure is an effective low-cost method to reduce the average speeds at the selected corridors....

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

Christofa, Eleni
Argote, Juan
Skabardonis, Alexander
2013

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...