Two students from Georgia Tech, Sara Khoeini and Adnan Sheikh, received the 2013 Freeway & Managed Lane Operations Meeting and Conference Best Student Paper Award at the 2013 Freeway & Managed Lane Operations Meeting and Conference (Mid-Year TRB Meeting) held in Atlanta on June 24, 2013.
Image courtesy of Nicole M. Crawford, State Road and Tollway Authority
Sara and Adnan are both third year Ph.D. students majoring in Transportation Systems, under their advisor Dr. Randy Guensler. The title of the paper is "The Fate of HOV Users after Pricing: Atlanta 's I-85 HOV2 to HOT3 Conversion."
Congestion pricing, especially in the form of new High Occupancy Toll (HOT) lane construction or conversion of existing carpool lanes into HOT lanes, has been increasingly planned or implemented across the United States. When it comes to pricing a facility which used to provide preferential treatment to carpoolers, such as High Occupancy Vehicle (HOV) lanes, one of the main policy concerns is the impact on carpooling (carpool formation and retention) which impacts traffic congestion, energy consumption, and regional air quality. In the case of Atlanta’s I-85, a relatively poor-performing carpool lane was converted to HOT3+, and variable pricing was implemented to ensure that HOT operations maintain a minimum speed of 45 mph 90% of the time during peak congestion periods. In the Atlanta I-85 HOV2 to HOT3 conversion, two-person carpools that originally used the HOV lane for free now must pay the same toll as single occupant vehicles to use the HOT lane. During a two-year HOV-to-HOT conversion performance monitoring project conducted by Georgia Tech, license plate data were collected during the weekday AM and PM peaks along the corridor. Vehicles representing frequent HOV users (i.e. the carpool market) prior to conversion were identified using license plate data. The HOT trip summary data, collected in the Express Lanes (applicable only for PeachPass holders after the conversion), were then utilized to investigate the travel frequency and willingness to pay of the HOT 3-person carpool market. Using socio-demographic data at the household level, the HOV market response to pricing is then investigated as a function of users’ attributes.