PATH

Reduce Emissions and Improve Traffic Flow Through Collaborative Autonomy

Patire, Anthony D. PhD
Dion, Francis PhD
Bayen, Alexandre M., PhD
2024

This report explores opportunities for employing autonomous driving technology to dampen stop-and-go waves on freeways. If successful, it could reduce fuel consumption and emissions. This technology was tested in an on-road experiment with 100 vehicles over one week. Public stakeholders were engaged to assess the planning effort and feasibility of taking the technology to the next level: a pilot involving 1000+ vehicles over several months. Considerations included the possible geographical boundaries, target fleets of vehicles, and suitable facilities such as bridges or managed lanes. Flow...

Assessment of the Applicability of Cooperative Vehicle-Highway Automation Systems to Bus Transit and Intermodal Freight: Case Study Feasibility Analyses in the Metropolitan Chicago Region

Shladover, Steven E.
Miller, Mark A.
Yin, Yafeng
Balvanyos, Tunde
Bernheim, Lauren
Fishman, Stefanie R.
Amirouche, Farid
Mahmudi, Khurran T.
Gonzalez-Mohino, Pedro
Solomon, Joseph
Rawling, Gerald
Iris, Ariel
Bozic, Claire
2004

This report presents the results of its performance assessment of the feasibility of applying cooperative vehicle-highway automation systems (CVHAS) to bus transit and freight movements in the metropolitan Chicago area. Cooperative vehicle-highway automation systems are systems that provide driving control assistance or fully automated driving and are based on information about the vehicle's driving environment that can be received by communication from other vehicles or from the infrastructure, as well as from their own on-board sensors.

Health of California’s Loop Detector System

Rajagopal, Ram
Varaiya, Pravin
2007

The California Department of Transportation (Caltrans) freeway sensor network has two components: the sensor system of 25,000 inductive loop sensors grouped into 8,000 vehicle detector stations (VDS) and covering 30,500 freeway direction-miles; and the communication network over which the sensor measurements are transported to Caltrans Traffic Management Centers. The sensor network is virtually the only source of data for use in traffic operations, performance measurement, planning and traveler information. However, the value of these data is greatly reduced by the poor reliability of the...

TRICEPS: An ATMIS Field Implementation for Control and Evaluation: Final Report

McNally, M. G.
Rindt, C.
Logi, F.
2002

This report summarizes a comprehensive research project directed toward the development and implementation of an Advanced Transportation Management and Information System (ATMIS) as part of the Caltrans Advanced ATMIS Testbed Program at the Institute of Transportation Studies, University of California, Irvine. The primary goal of this project was to implement this prototype ATMIS, designated TRICEPS (Testbed Realtime Integrated Control and Evaluation Prototype System), in the Irvine sub-area of the Advanced Testbed network. This sub-area represents a well-defined freeway corridor with a...

Experimental Verification of Discretely Variable Compression Braking Control for Heavy Duty Vehicles

Vahidi, Ardalan
Stefanopoulou, Anna G.
Farias, Phil
Tsao, Tsu Chin
2003

In this report a recursive least square scheme with multiple forgetting factors is proposed for on-line estimation of road grade and vehicle mass. The estimated mass and grade can be used to robustify many automatic controllers in conventional or automated heavy-duty vehicles. We demonstrate with measured test data from the July 26-27, 2002 test dates in San Diego, CA, that the proposed scheme estimates mass within 5% of its actual value and tracks grade with good accuracy. The experimental setup, signals, their source and their accuracy are discussed. Issues like lack of persistent...

Long Term Impacts of California’s Graduated Licensing Law of 1998

Cooper, Douglas
Gillen, David
2005

In July 1998 California changed its graduated driver licensing laws (GDL) for new drivers under the age of 18 to include restrictions on hours of driving, carrying teen-age passengers, and requiring more adult supervised driving practice. With fatal and injury crash data from California's Statewide Integrated Traffic Records System, this study, sponsored by Caltrans, used standard regression analysis as well as the Bai-Perron stochastic multiple structural break model to determine the effect of the law on teen-age passengers and crash rates of 16 year-old drivers. We found that in the four...

Control Strategies For Transit Priority

Skabardonis, Alexander
1998

This report discusses the major factors which influence the benefits from transit priority. It reviews existing control strategies that have been implemented in signal controlled networks. A number of control strategies to improve transit performance are proposed along with an analysis technique to evaluate their effectiveness. The strategies were tested on a major arterial. Recommendations are given, based on the results.

Weaving Analysis, Evaluation and Refinement

Skabardonis, Alexander
Kim, Amy
2010

Weaving sections are common design elements on freeway facilities such as near ramps and freeway to-freeway connectors. When the traffic demands exceed the capacity at weaving areas congestion may occur, which affects the operation of the entire freeway section. Traffic operational problems also may exist at weaving areas even when traffic demands are less than capacity because of the complexity of vehicle interactions, resulting in poor level of service (LOS) and potential safety problems. Existing procedures for the design and analysis of freeway weaving sections have several...

Traffic Modeling To Evaluate Potential Benefits Of Advanced Traffic Management And In-vehicle Information Systems In A Freeway/Arterial Corridor

Gardes, Yonnel
1990

This study includes a literature review of existing traffic simulation models potentially suited for evaluating advanced traffic control strategies and in-vehicle information systems within an integrated freeway/ arterial corridor. Chapter 1 presents a literature review and identification of candidate models. Chapter 2 contains a preliminary screening of candidate models. Chapter 3 presents an in-depth evaluation of short list of models. And, Chapter 4 gives conclusions of the research and recommendations for future directions.

An Integrated Physical/link-access Layer Model Of Packet Radio Architectures

Polydoros, Andreas
1994

The goal of this effort is to devise and analyze an integrated Physical/ Link-Access Layer Model of packet Radio Architectures, with application to the PATH/IVHS (Intelligent Vehicle Highway Systems) communication sub- system design between vehicles and infrastructure, as well as between vehicles on the move. The present report contributes to a generic conceptual model for system evaluation which can be used for quantification of the interaction between network layers. The research tasks that have been performed for achieving the project objectives include collection of data requirements...