Atlanta I-85 HOV-to-HOT Conversion: Analysis of Vehicle and Person Throughput

This report summarizes the vehicle and person throughput analysis for the High Occupancy Vehicle (HOV) to High Occupancy Toll (HOT) Lane conversion in Atlanta, Georgia, undertaken by the Georgia Institute of Technology research team. The team tracked changes in observed vehicle throughput on the corridor and collected average vehicle occupancy (persons/vehicle) data to assess changes in person throughput. Traffic volumes were collected by vehicle detection systems (VDS) systems on the Georgia NaviGAtor system and the team implemented a large scale quarterly data collection effort for vehicle occupancy across all travel lanes. Between the baseline year (2011) and HOT implementation year (2012), significant changes were noted in both the vehicle and person throughput on the corridor at Center Way. Vehicle throughput on the I-85 HOT corridor decreased by about 6.6% (2698 vehicles) during the morning peak period, but only by about 2.9% (1148 vehicles) during the afternoon peak period. Average vehicle occupancy (persons/vehicle) also decreased during the same period. Reduced vehicle throughput and decrease in observed vehicle occupancy had a synergistic impact on estimated corridor person throughput, which declined significantly at a much faster rate than vehicle throughput. While traffic volumes declined by 6.6%, person throughput concurrently declined by about 9.9% (4868 individuals). While traffic volumes declined by approximately 2.9% in the afternoon peak period, person throughput concurrently declined by about 6.3% (3123 individuals). The data reveal that the majority of two-person carpools have been diverted from the HOV lane into the general purpose lanes after HOT lane implementation. Based upon vehicle throughput and occupancy distributions, the largest reduction in vehicle throughput in both the morning and afternoon peak periods came from a reduction in carpools (HOV2 and HOV3+ vehicles). Carpool mode share declined by more than 30% in the AM peak and by 25% in the PM peak, and average managed lane vehicle occupancy decreased from approximately 2.0 persons/vehicle to approximately 1.2 persons/vehicle.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Maps; References; Tables;
  • Pagination: 142p

Subject/Index Terms

Filing Info

  • Accession Number: 01529320
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-GA-13-10-03, 10-03
  • Contract Numbers: SPR00-0009-00-297 (RP 10-03)
  • Created Date: Jun 3 2014 1:59PM