The Effects of Bus Ridership on Airborne Particulate Matter (PM10) Concentrations

Jaeseok Her,Jae Lee,Sungjin Park

doi:10.3390/su8070636

Abstract

Air pollution caused by rapid urbanization and the increased use of private vehicles seriously affects citizens’ health. In order to alleviate air pollution, many cities have replaced diesel buses with compressed natural gas (CNG) buses that emit less exhaust gas. Urban planning strategies such as transit-oriented development (TOD) posit that reducing private vehicle use and increasing public transportation use would reduce air pollution levels. The present study examined the effects of bus ridership on airborne particulate matter (PM10) concentrations in the capital region of Korea. We interpolated the levels of PM10 from 128 air pollution monitoring stations, utilizing the Kriging method. Spatial regression models were used to estimate the impact of bus ridership on PM10 levels, controlling for physical environment attributes and socio-economic factors. The analysis identified that PM10 concentration levels tend to be lower in areas with greater bus ridership. This result implies that urban and transportation policies designed to promote public transportation may be effective strategies for reducing air pollution.

Highlights

Many cities suffer from air pollution caused by rapid urbanization and the increased use of private vehicles [1,2]
According to the Organisation for Economic Co-operation and Development (OECD), the number of deaths attributable to air pollution rose by about 4% from 2005–2010, while the economic costs amounted to approximately 3.5 trillion US dollars annually [15]
Chakraborty and Mishra [35] attempted to establish the relationship between transit ridership and land use variables using ordinary least-squares (OLS) and spatial error modelling (SEM), classifying the state of Maryland, USA, into urban, suburban, and rural areas; their results showed that determinants and coefficients varied across the three area types

Summary

Introduction

Many cities suffer from air pollution caused by rapid urbanization and the increased use of private vehicles [1,2]. By 2015, every bus in Seoul was running on CNG, while about 80% of buses in other cities in the capital region had been converted [22] Urban planning strategies, such as transit-oriented development (TOD), posit that decreased private vehicle use and increased public transportation use would reduce air pollution levels [11,19,23,24,25,26,27]. We utilized environmental variables that affect traffic and air flow—through street-canyon effects—such as intersection density, building coverage ratio, and land-use diversity These variables controlled for the effects of urban geometry related to the dispersion of PM10 [30,31]. The rest of this paper consists of a review of relevant theories and empirical studies, an introduction to the study settings and methods, an analytical report of the results, and a discussion of those results

Background

Context

Data and Key Variables

Spatial Regression Model

Analysis Results