Correlations between public transportation access and air quality: a case study of Utah County, Utah

Abstract

Utah County, in the State of Utah in the United States, is one of the fastest-growing regions in the country - expecting to triple its population within the next fifty years. However, as of 2017, the United States Environmental Protection Agency already lists the region as non-compliant with safe air regulations, with air pollution in the county being rated one of the worst in the United States. On top of this, the area currently has limited public transportation options, forcing a majority of people to use private automobiles for commuting. This dissertation studied the correlation between increasing the range and access of public transportation in the county and decreasing the rate of expected air pollution. The study was divided into two areas of research. First, predictive modeling of air pollution, based on current conditions and expected population growth, was performed to determine future conditions if no action were to be taken. After determining these figures, the study explored the impact of opening a light-rail transit line along an existing corridor through the county - specifically, the amount of vehicle miles reduced and, subsequently, the amount of reduced air pollution.

Under current conditions, it was determined that airborne pollution in the area would significantly rise by 2040 - between 20-30% depending upon the pollutant. The opening of the new desired light rail line would not make any significant impact in decreasing pollution in the area, reducing growth rates by less than 1%. Further study into the subject, and expansion of current plans for public transportation in the area, may lead to more significant changes.