Metro-line expansions and local air quality in Shenzhen: Focusing on network effects

Document Type

Journal Article

Publication Date

2024

Subject Area

place - asia, place - urban, mode - subway/metro, infrastructure - station, land use - impacts, land use - transit oriented development, land use - urban density, planning - environmental impact, planning - service improvement, technology - emissions

Keywords

Urban rail, Metro system, Network effects, Traffic diversion, Pollution abatement, Difference-in-differences, Shenzhen

Abstract

We examine the air-quality effects of urban-rail development in Shenzhen, taking a difference-in-differences approach. This study is motivated by existing mixed evidence on the rail-pollution relationship, which we associate with the dynamic nature of the relationship itself. Our results demonstrate that the relationship varies by time, depending on network density and scale. New station openings had no significant impacts on local air quality or even worsened it until the 2010 metro-line extension, when Shenzhen’s metro network density was still low, with limited spatial service coverage. However, the 2016 extension significantly abated air pollution as the network grew denser and more comprehensive. The rail-driven anti-pollution effects tended to be further strengthened with externalities arising from improved network connectivity, spilling over the effects beyond newly opened stations to preexisting ones. Also, metro stations in proximity to neighborhoods that share key characteristics in transit-oriented development tended to generate a greater anti-pollution effect.

Rights

Permission to publish the abstract has been given by Elsevier, copyright remains with them.

Comments

Transportation Research Part D Home Page:

http://www.sciencedirect.com/science/journal/13619209

Link to Full Text

Share

COinS