University of California Institute of Transportation Studies

The Carbon Reduction Program (CRP) requires transportation projects to demonstrate measurable reductions in transportation-related greenhouse gas (GHG) emissions, but the impact of priced managed lanes and related roadway pricing projects on emissions can vary. Thus, there is a need for a transparent framework that can place evidence within a common statewide emissions metric. This report develops a screening framework to translate project-level GHG impact data from CRP-relevant projects in California into a wider statewide framework for emissions accounting. The preliminary framework separates the direct effects of a priced managed lane project on roadway travel demand from its indirect effects. In a case study analysis, the I-580 managed project lane is predicted to directly increase VMT and CO2 emissions through induced travel demand. However, reinvestment of the lane’s revenue in regional transit is projected to reduce VMT and CO2e emissions. In conclusion, a CRP GHG accounting should evaluate direct roadway effects and reinvestment effects separately before integrating them within a common statewide emissions accounting framework.