01662898

Component

Recent studies have suggested that automobile pollution poses significantly more harmful health impacts than previously realized. Light-rail transit (LRT) is a major type of transportation infrastructure, but there has been little research assessing the air quality effects of LRT based on the actual air pollution data. This study aimed to assess the effect of LRT on automobile-related air pollution in Houston. Specifically, we examined the effects of LRT on key tailpipe pollutants—carbon monoxide and acetylene—as well as other traffic pollution surrogates referred to as BTEX (benzene, toluene, ethylbenzene, and xylene), measured from ambient air monitoring stations. An interrupted time series design and analysis were used to determine the impact of an intervention, where the intervention was the opening of an LRT on January 1, 2004, with two years (2002–2003) of before and two years (2004–2005) of after period data. The authors found that the opening of the LRT was associated with statistically significant reductions in the hourly carbon monoxide level and the daily maximum carbon monoxide level of roughly 5% and 32%, respectively, as well as statistically significant reductions in the levels of acetylene, toluene, and xylene of about 47%, 69%, and 55%, respectively, at the exposure sites. These data provide support for the air quality benefits of LRT, especially through the reduction of traffic-related air pollution. This study’s findings also emphasize the importance of developing effective measures to assess traffic-related pollution and call for advanced data collection strategies of additional data, including traffic volume and speed data.

This paper was sponsored by TRB committee ADC20 Standing Committee on Transportation and Air Quality.

18-00622

English

25p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; Maps; References; Tables

Air pollution; Carbon monoxide; Exhaust gases; Light rail transit; Time series analysis

Acetylene

Houston (Texas)

Environment; Planning and Forecasting; Public Transportation

Transportation Research Board Annual Meeting 2018 Paper #18-00622

TRIS, TRB, ATRI

Jan 8 2018 10:10AM