Project Summary:
The Georgia Tech team will update and expand the vehicle occupancy, vehicle throughput, and person throughput study conducted for the State of Georgia from 2010-2013. The original study examined the effects of the I-85 HOV to HOT conversion project on occupancy and throughput. The new assessment will cover the extension of the I-85 HOT lanes (I-85 Extension) and the new reversible Northwest Corridor (NWC) express lanes, which are both opening in 2018, as well as the reversible I-75 South Metro express lanes (I-75 S) that opened in 2017. Baselined data will be collected in 2018 and one year later in 2019 to assess changes in throughput over the one-year period, which includes a before-and-after assessment of the I-85 Extension and NWC facilities. The team will further modernize the roadside data collection method by shifting from keypads and notebooks to a graphic user interface on field tablets. Based upon the analyses of data collected in the previous study, the team concluded that statistically-significant occupancy results will be obtained by collecting data only during one season (instead of all four seasons). Morning and evening peak period data for the peak commute direction will be collected for five days at each location each year (completed baseline data collection in early November). The team will assess baseline vehicle and person throughput on each facility, assess changes in vehicle and person throughput in each corridor between the fall 2018 and fall 2019 sampling efforts. The team will assess express bus vehicle and person throughput using data provided by SRTA (Xpress), Cobb Linc, and Gwinnett Community Transit. In spring 2019, the team will deploy an online carpool survey and invite 40,000 Georgia Express Lane users to participate. The team will conduct focus groups to follow-up on survey findings. The team will also assess relationships between household demographics, carpooling, and managed lane use in each corridor. The team will deliver an interim report summarizing fall 2018 data collection and a final report summarizing overall changes and other project findings.