Christopher Hoehne | National Renewable Energy Laboratory

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Presentation Description

Efficient and accessible transit systems can allow greater transportation options to residents, decrease the need for driving, and ultimately support reaching decarbonization goals. While transit systems may lack in flexibility and speed compared to cars, they have benefits in terms of better energy efficiency (higher occupancy) and greater affordability. These positive facets of transit often get overlooked in traditional access calculations that primarily use travel time (or speed) of a mode in quantifying access to opportunities. To remedy this, NREL researchers developed the Mobility Energy Productivity (MEP) metric that builds on traditional access metrics, and considers time, energy, and cost efficiencies of a mode in quantifying access to opportunities. To assess changes in transit access efficiency pre- and post-COVID-19, we calculate job access metrics across over 50 of the largest U.S. cities using the MEP framework. We utilize the Longitudinal Employer-Household Dynamics and General Transit Feed Specification datasets from 2019 and 2023 to measure changes in access across four different travel time thresholds. To examine equitable transit access to jobs, we also compare trends for low-to-moderate income populations (<80% of the Area Median Income) versus the general population. When estimating the population-weighted mean changes to job access for each city and time threshold, we find varying trends in both categories. From 2019 to 2023, most cities had small changes to 10 minute job access with the average resident gaining or losing access to no more than 1,000 jobs. However, for 20, 30, and 40 minute travel times, many locations across cities had gains or losses in the tens of thousands of jobs accessible via transit. This may indicate major cities across the US are diverging in transit access to jobs for longer journeys. Cities were split roughly 50/50 in greater vs lesser transit access to jobs in 10 for the low-to-moderate income group, but approximately two-thirds and four-fifths of cities had greater transit access for this group in 20 and 40 minutes, respectively. Across all cities examined, the low-to-moderate income population had 7% greater access to jobs by transit in 40 minutes compared to the average resident. These metrics can help cities measure equitable transit access and improvements over time and offer insights to provide affordable and efficient transport options to support reaching decarbonization goals.

Speaker Biography

Dr. Hoehne is a Research Scientist and project leader at the National Renewable Energy Laboratory in the Center for Integrated Mobility Sciences. His research focuses on computational modeling and analysis of transportation systems with interests in accessibility, decarbonization, parking, land use, equity, and urban heat.

Christi Nakajima is a Senior Research Analyst at the American Council for an Energy-Efficient Economy. She conducts research and analysis on VMT reduction policies and transportation electrification and is the author of the Transportation Chapter in the recent 2024 City Clean Energy Scorecard.

Co-presenters

Cemal Akcicek
National Renewable Energy Laboratory

Sailesh Acharya
National Renewable Energy Laboratory

Venu Garikapati
National Renewable Energy Laboratory

Christi Nakajima
American Council for an Energy-Efficient Economy

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