Experience with congestion pricing on I-85 in Atlanta
Atlanta, Georgia, United States
Atlanta Congestion Reduction Demonstration: Interim Technical Memorandum on Early Results
Summary Information
The Atlanta Congestion Reduction Demonstration (CRD) project is one of six sites funded by the U.S. DOT through the Urban Partnership Agreement (UPA) and national CRD program to demonstrate congestion pricing and other supporting strategies. The projects are focused on reducing traffic congestion along the I-85 corridor. The Atlanta CRD was the conversion of existing 2+ person high occupancy vehicle (HOV) lanes to dynamically-priced 3+ person high-occupancy toll (HOT) lanes, called Express Lanes, on approximately 16 miles of I-85 northeast of Atlanta. Other Atlanta CRD projects that are being evaluated include transit enhancements, where 36 new buses enabled operation of five new routes on the corridor and park-and-ride lot enhancements.
Evaluation data were collected before and after the conversion to assess impacts on commuters, stakeholders, agency operations, and the environment. "Before" data were collected from September 2009 to September 2010 and "after" data were collected from October 2011 to September 2012. Initial results from a preliminary analysis are shown below. A final evaluation will be provided at the end of the project.
FINDINGS
Transit Analysis
- Annual boardings on the I-85 Xpress bus service increased by seven percent while other areas increased by only three percent.
- Park-and-ride lot use also increased at three out of four lots evaluated. The increased transit use was due in part to increased gasoline prices.
- Traffic sensor data suggested benefits for Express Lanes, but mixed results for general purpose lanes.
- During the first four months of operations the monthly number of trips during morning peak periods grew 54 percent on Express Lanes.
- Excluding the first two weeks when toll rates were in flux, the maximum toll price increase during the four month period increased from $1.55 to $4.25.
- The number of tolled trips increased at a greater rate than the number of non-tolled trips (67 percent compared to 32 percent, respectively).
Moving up to a 3+ person requirement for free travel in the Express Lanes, survey data indicated that
- 39 percent of carpoolers would likely switch to general purpose lanes to avoid paying tolls.
- 15 percent would switch to driving alone.
- 9 percent would look for another person to create a 3 person carpool.
- 5 percent would move to transit.
