Georgia TechSchool of Civil and Environmental Engineering
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Commute Atlanta Study: Overview

After more than two years of planning, the Georgia Institute of Technology, School of Civil and Environmental Engineering implemented the Commute Atlanta Study in 2003. This ongoing study is sponsored by the Federal Highway Administration, Georgia Department of Transportation, and Georgia Institute of Technology. The Commute Atlanta study is collecting travel data from instrumented vehicles throughout the Atlanta metropolitan area to provide better information on where, when, and under what conditions people drive in Atlanta. The study will help transportation planners and traffic engineers to understand how we can make the transportation system safer and more efficient, and will provide data for use in improving our regional transportation system. A variety of research initiatives are associated with Commute Atlanta, including research in the areas of travel behavior, value pricing, safety, traffic operations, and motor vehicle emissions.

In 2004, Commute Atlanta monitored one full year of baseline travel activity from more than 275 participating households. These volunteer households allowed the research team to professionally install a GT Trip Data Collector in their vehicles. Approximately 465 vehicles in these households were equipped with instrumentation to monitor second-by-second vehicle speed and position for every trip. Researchers remotely monitor the travel patterns of these vehicles, uploading vehicle and engine operating data via a cellular data connection. General travel data, such as number of trips per household per day and selected travel routes, are used to evaluate transportation demand models currently used in Atlanta's transportation planning process. Vehicle position and speed data are used to identify locations of recurrent traffic congestion.

Two-day travel diaries and employer commute options surveys were also collected from participating household and employers. The 2004 baseline data set comprises more than 650,000 vehicle trips and serves as baseline data for a variety of the research efforts. To date, the research team has monitored more than 1.7 million vehicle trips and we currently manage more than 2 terabytes of processed data. This wealth of data has resulted in the publication of numerous research papers.

More than 100 households participated in Phase II value-pricing research designed to assess household travel response to simulated payment of transportation costs on a per-mile basis. A similar number of households will experience real-time congestion pricing later this year. Analytical efforts for this project are expected to continue throughout 2007.

Project overview from the George Tech Whistle, October 2003


Commute Atlanta: Value Pricing Initiative

Purpose of Study

Commute Atlanta's Value Pricing program is designed to assess the effects of converting fixed automotive operating costs into mileage-based and congestion-based operating costs. Consumer response to the economic stimulus is expected to provide insight into the potential effects of congestion pricing, pay-as-you-drive insurance pricing, gas tax replacement, and other value pricing initiatives.

Phase II: Travel Reduction Incentives

The Phase II effort of the Commute Atlanta study ran from October 2005 through June 2006. In Phase II, the impact of mileage-based incentives is examined through pricing simulation. Each quarter, an incentive account was established for each household, based upon the number of miles traveled during the same quarter in the baseline year and the quarterly cent/mile rate. This cent/mile rate increased each quarter, from 5 cents/mile in the first quarter to 15 cents/mile in the third quarter. For every mile driven by the household, the incentive account was depleted by the quarterly cent/mile rate. Households that reduced their miles of travel relative to the baseline received a check each quarter for the amount remaining in their incentive account. Households that continued their pre-existing driving patterns or increased travel were not be penalized. The research team monitored the changes in driving patterns and participants over a nine month period. More than half of the households reduced their travel and more than $15,000 in incentive checks for associated with decreased travel were issued. The research team is currently undertaking detailed case study and statistical analyses of household travel response (by trip type) as a function of household demographics, travel mode constraints, and relevant employer incentives (parking costs, transit accessibility, etc.) to examine the relationships between gasoline price increases, the incentives offered, and changes in travel behavior changes. The final case study report is scheduled for completion in late 2006.

Phase III: Congestion Pricing

The research team is currently in final preparation for the Phase III value pricing research deployment. In Phase III, real-time congestion pricing will be implemented for approximately 100-120 participating vehicles. Phase III uses a similar simulation approach. However, in this effort a 20 cent/mile congestion surcharge will be assessed to commute trips undertaken under congested freeway conditions (speeds < 40 mph). Households that shift their commute travel out of peak congested periods will retain a significant portion of the incentive account. The researchers will be monitoring vehicle location, current congestion levels, and communicating the congestion price to the driver in real-time through the onboard equipment and in-vehicle display terminal. Data from the Phase III effort will help researchers to assess the importance of congestion pricing on changes in travel time departure as a function of work location and household demographic characteristics.



For more information about the Commute Atlanta research program, please call our hotline or send us an e-mail:

Hotline: 404-385-2376