Available at: https://digitalcommons.calpoly.edu/theses/2908
Date of Award
3-2024
Degree Name
MS in Civil and Environmental Engineering
Department/Program
Civil and Environmental Engineering
College
College of Engineering
Advisor
Anurag Pande
Advisor Department
Civil and Environmental Engineering
Advisor College
College of Engineering
Abstract
Although vehicle miles traveled (VMT) has become the standard for assessing transportation related impacts in California, some have concerns that many VMT estimates are not properly grounded or informed by real world data, potentially resulting in flawed estimates and impact assessments. This is especially true of special generators, like college and university campuses, which have complex travel patterns distinct from that of the general public. This thesis attempts to resolve a significant disparity observed between two credible VMT estimates for Cal Poly’s campus wide VMT. As part of a campus master planning effort, a VMT estimate was produced in 2019 for an environmental impact report (EIR), using a travel demand model (TDM) based approach. This result was quite divergent from a prior 2018 estimate which used contemporaneous survey data (a data source often used to ground and calibrate/validate TDM results), leaving an approximate difference of 200 million VMT to be accounted for. In an attempt to address this disparity, this investigation considered three distinct analyses, including a quantitative assessment of variability of the 2018 travel survey estimate (via a bootstrap), an accounting of missing VMT not captured by the 2018 estimate, and a final comparison of the reliability and credibility of the 2018 and 2019 estimates based on both qualitative (scope and methodological issue of the estimates) and quantitative (benchmarking reported metrics) factors. Based on this investigation’s findings, although the disparity can be partially explained, a significant deficit of over 100 million VMT remained, suggesting the 2019 estimate may have overstated campus VMT and its impacts. It also suggests that campuses have significant VMT generating functions beyond the frequently studied commuter and residential travel behaviors. The lessons learned from this thesis provide a roadmap to improving future VMT estimates for college and university campuses as well as how regulators may approach setting appropriate analysis requirements and impact thresholds for these unique land uses.