The Impact of Light Rail Construction on Regional On-Road CO2 Emissions Per Capita

As per capita on-road CO2 emissions continue to rise in the US, a better understanding of the emissions-reduction benefits of building a new transit system is needed. Employing a novel quasi-experimental event study methodology, the results of this paper indicate that after 8 years of operation, construction of a light rail system has led to a small but significant reduction in regional on-road CO2 per capita of 8.4% - 12.9%. These results are robust to selection of control group and are larger than the estimated impact of light rail construction on population density (1.0%), evaluated in a comparative quasi-“placebo” study.