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This ongoing, multi-part research initiative explores the intersection of urban transportation, land use planning, and impacts of mobile-source air pollution on human health and the economy, using Chengdu, Sichuan as a case city.

As with the China Project in general, it is shaped by independent research inquiry more than direct policy applications. It pursues innovations in basic research—on interdisciplinary topics and ultimately for cities in general—needed to strengthen capacities that can inform policy practice. A number of separable but linked faculty-led studies are underway, including original data collection, field interviews, development and application of models, and analyses. Individual components have timelines, but the initiative as a whole is open-ended and intended to evolve as research interests of participants dictate.

Publication will occur in peer-reviewed journals (the first accepted or in review, noted below) and then in an edited collection. The program has also reported progress in two research workshops in Chengdu with municipal officials and in the 2007 seminars of the China Project.

The Chengdu initiative was motivated in part by the transport sector research in Clearing the Air, and builds on some of its methods and component structure. The Chengdu program is developed and managed by Chris Nielsen (Harvard School of Engineering and Applied Sciences, HSEAS) and HE Kebin (Tsinghua University, Department of Environmental Science and Engineering, DESE), advised by Peter P. Rogers (HSEAS) and working with researchers at Harvard, Tsinghua, Peking University, and several other institutes.

Transportation and Land Use

One team led by Peter P. Rogers (HSEAS) and Sumeeta Srinivasan (HSEAS and Harvard Center for Geographic Analysis) is investigating the relationship of land use to travel behavior. It uses results of an original 1001-household survey that the China Project conducted in fall of 2005 in partnership with SHEN Mingming and the Research Center for Contemporary China (RCCC) of Peking University (PKU). Several initial analyses are now forthcoming or submitted (Srinivasan 2007a; Srinivasan 2007c; Zegras and Srinivasan 2007; see publications).

Srinivasan is also collaborating with Joan Walker (Boston University, Center for Transportation Studies) and student LI Jieping to use the Chengdu survey to develop a mode choice travel behavior model for data-constrained contexts like China (Walker et al. 2007; see publications). They have also developed a street network model of Chengdu including bus routes (see figure) to estimate alternatives to travel mode choices revealed in trip diaries of the household survey.

Mobile-Source Emissions, Air Quality, and Human Exposure

A field study of vehicle activities is planned by HE Kebin (Tsinghua DESE) and colleagues in partnership with the China Project. The team will collect three kinds of data in Chengdu, sampling representative streets (on videotape) and parking areas (via on-foot survey) for an improved in-use vehicle distribution than available through official registration, and characterizing driving cycles and start patterns using GPS receivers and voltage sensors mounted onboard sampled vehicles.

WANG Shuxiao (Tsinghua DESE) and students are modeling the fate of emissions, including air transport and chemical transformation and human exposures, using the intake fraction method used in Clearing the Air. With advisory support of Harvard School of Public Health (HSPH) faculty, they aim to estimate the comparative importance to population health risk of street-scale exposures to near-source pollutants (using street canyon models) and urban-scale exposures to primary pollutants (as in the figure, using a regional air quality model).

Health Valuation and Cost Analyses

Following a wage-differential study valuing health risk in China (Guo and Hammitt 2007; see publications), James K. Hammitt (HSPH), GUO Xiaoqi (Harvard China Project and Ohio State University, OSU) and Timothy Haab (OSU) have now completed a contingent valuation assessment in Chengdu (Guo et al. 2007; Guo 2006; see publications). This study estimates the values that Chengdu citizens place on the health damages associated with mobile-source pollution. It used the same household survey noted above, conducted by Peking University with a GPS-based, geospatial sampling to insure inclusion of non-registered "floating" population (see figure illustrating spatial randomization of sampled survey districts).

These and researchers in other Chengdu project areas are now considering how to combine results of valuation and components above to estimate costs and benefits of possible transportation interventions. These will focus on the transit system, for example, pollution control retrofits of buses and prospective Bus Rapid Transit lines.

Reconciling Transport and Air Quality Planning

Arnold Howitt (Kennedy School of Government, KSG), Carlos Wing-Hung LO (Department of Management, Hong Kong Polytechnic University), and student WANG Rui (KSG) are investigating the institutional and policy context of reconciling urban transport and air quality objectives in Chengdu. The goal is to place the challenges in a multi-level regulatory context, examining how the national government implements transport-related air quality laws, how they are carried out at the province and city level, and how significant are efforts to establish cooperation across jurisdictions.