TY - JOUR
T1 - Quantifying the environmental impacts of increasing high occupancy vehicle lanes in the United States
AU - Javid, Roxana J.
AU - Nejat, Ali
AU - Hayhoe, Katharine
N1 - Publisher Copyright:
© 2017 Elsevier Ltd
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2017/10
Y1 - 2017/10
N2 - To what extent will increasing High Occupancy Vehicle (HOV) lane-kilometer incentivize carpooling and reduce emissions of air pollutants and greenhouse gases? To answer these questions, we develop a multiple regression model relating HOV lanes and other socioeconomic factors to carpooling propensity in all 50 U.S. states and the District of Columbia, then calculate the extent to which increasing HOV lane-kilometers would lead to reductions in carbon dioxide equivalent (CO2e) and major air pollutants across the U.S., by state. Increasing HOV lane extent has the greatest potential to reduce annual CO2e in the District of Columbia, followed by Hawaii and New York. The smallest potential is found in states with the lowest population density, led by North Dakota. We then explore the extent to which recommendations made at one level of data aggregation (that of individual states) may be valid for another level, such as individual counties. The only state with sufficient data available to disaggregate the model to the county level is California, where we found a lower potential for state-wide CO2e emission reductions under the county-level model as compared to the state-level model (0.69% as compared to 1.08%, under the same hypothetical scenario), albeit with significant differences in emission reduction potential between counties with higher vs. lower population densities. This analysis demonstrates the potential to generate generalizable insight into the magnitude of vehicle emission reductions that might be achieved through expanding HOV lanes, and highlights the importance of data disaggregation in identifying the optimal locations for potential reductions.
AB - To what extent will increasing High Occupancy Vehicle (HOV) lane-kilometer incentivize carpooling and reduce emissions of air pollutants and greenhouse gases? To answer these questions, we develop a multiple regression model relating HOV lanes and other socioeconomic factors to carpooling propensity in all 50 U.S. states and the District of Columbia, then calculate the extent to which increasing HOV lane-kilometers would lead to reductions in carbon dioxide equivalent (CO2e) and major air pollutants across the U.S., by state. Increasing HOV lane extent has the greatest potential to reduce annual CO2e in the District of Columbia, followed by Hawaii and New York. The smallest potential is found in states with the lowest population density, led by North Dakota. We then explore the extent to which recommendations made at one level of data aggregation (that of individual states) may be valid for another level, such as individual counties. The only state with sufficient data available to disaggregate the model to the county level is California, where we found a lower potential for state-wide CO2e emission reductions under the county-level model as compared to the state-level model (0.69% as compared to 1.08%, under the same hypothetical scenario), albeit with significant differences in emission reduction potential between counties with higher vs. lower population densities. This analysis demonstrates the potential to generate generalizable insight into the magnitude of vehicle emission reductions that might be achieved through expanding HOV lanes, and highlights the importance of data disaggregation in identifying the optimal locations for potential reductions.
KW - Air pollutants
KW - COe
KW - Carbon emission reductions
KW - Carpooling
KW - HOV lanes
KW - Transportation Infrastructure
UR - http://www.scopus.com/inward/record.url?scp=85027233929&partnerID=8YFLogxK
U2 - 10.1016/j.trd.2017.07.031
DO - 10.1016/j.trd.2017.07.031
M3 - Article
AN - SCOPUS:85027233929
VL - 56
SP - 155
EP - 174
JO - Transportation Research Part D: Transport and Environment
JF - Transportation Research Part D: Transport and Environment
SN - 1361-9209
ER -