Causal Analysis of Public Transport Interventions and impacts on air quality

Air quality is highlighted as a global issue in recent decades, resulting from an obvious deterioration in air quality and an understanding of its adverse impact on human health and ecosystem. Transport sector is one of the main sources of air pollution, particularly for carbon monoxide and nitrogen oxides. Governments around the world have made vast investments in public transport, considering its potential in reducing road traffic volume, mitigating road congestions and improving air quality.

However, the evaluation of the actual impact of public transport on air quality can be complicated because of the interactions among urban subsystems. These could include the interactions among the land use pattern and transport, different demand elasticity of various passenger groups, relocation of firms and households, reactions among air pollutants, the interplay between the air pollutants and meteorological factors, and the complex mechanism of air pollutant dispersion.

This project focuses on evaluating the causal impact of public transport interventions on air quality with a series of causal inference methods, considering the complicated mechanism of interactions among urban subsystems. This could provide policymakers with a guidance in following investment and assist in making gradual amendments in policies with systematic considerations.

Research team:

• Dr Marc Stettler
• Liang Ma