Bay Bridge

Development and Evaluation of Selected Mobility Applications for VII

(Project funded by FHWA Exploratory Advanced Research Program, with cost sharing from the California Department of Transportation and University of California)

This project was developed to expand the frontiers of thinking about vehicle-infrastructure cooperation, beyond those in the original national VII initiative, in several dimensions:

  • Use DSRC wireless technology in both vehicle-vehicle and vehicle-infrastructure-vehicle modes to improve mobility and efficiency of road transportation, not just safety. By doing this, it should be possible to reduce congestion, fuel consumption and emissions of CO2 and category pollutants, while saving money.

  • Stimulate thinking about applications and time horizons that are beyond "Day One" of VII deployment.

  • Emphasize innovative applications that are not currently in "mainstream" thinking but have real potential to help solve transportation problems.

It is developing and evaluating the effectiveness of three primary mobility-enhancing applications:

  1. Traffic-responsive cooperative adaptive cruise control (CACC), using vehicle-vehicle communication for close coordination of vehicle maneuvers, vehicle-infrastructure communication for collecting probe vehicle data about traffic conditions, and infrastructure-vehicle communication for providing set speed and gap instructions to the vehicles.

  2. Dynamic speed advisories to drivers, to help maximize the effective capacity of highways at bottlenecks, and provide a second dimension of freeway traffic control complementary to ramp metering. This uses vehicle-infrastructure communication for collecting probe vehicle data and infrastructure-vehicle communication for providing individualized advisory speeds.

  3. Automated truck platoons, enabling heavy trucks to drive at very short spacings to increase the capacity of a truck lane and reduce aerodynamic drag and energy consumption. This uses vehicle-vehicle communication to enable closely-coordinated vehicle following and cooperative maneuvering of the trucks.

This project is building on current and prior PATH projects that have provided a strong technical foundation for the new research. We are developing prototype vehicle systems and testing them to prove technical feasibility with a small number of vehicles, then using simulations to assess their effectiveness when scaled up to full deployment with large numbers of equipped vehicles. Assuming successful results in these activities, we hope to stimulate new research support to advance the systems to deployability.

The Concept of Operations we have developed for this project is available for download here.

The Deployability analysis report we have developed for this project, reviewing the availability of many of the enabling technologies for vehicle automation, is available for download here.

Information about the prior and current PATH projects that have provided the technical foundations for this work is available from a variety of online sources:

Reports on our predecessor projects evaluating the impacts of CACC on highway lane capacity:
PRR 2001-18  and  PRR 2004-22

Report on the development and initial testing of the CACC vehicles being used for this project: PRR-2009-23

Website for the Tools for Operations Planning (TOPL) project, which is providing many of the analysis tools for assessing traffic impacts:

Reports on predecessor projects on improving ramp metering strategies: PRR 2004-44 and PRR 2006-21 and TO 6329 (TBA)

Report on development of truck platooning control system and other heavy vehicle automation systems: PRR 2005-23

Video of the previous truck platoon experiments from 2003 can be seen at: Truck Platoon at Crows Landing, Patterson, CA

Report on experimental evaluation of fuel savings from truck platooning: PRR 2004-20

Report on measuring emissions from trucks in real time, individually and platooned: PRR 2005-01

Underlying much of this work was the earlier PATH research on vehicle automation conducted under the National Automated Highway Systems Consortium (NAHSC) between 1994 and 1998. Documentation of this work is available at:

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