A team including Professor Jason Cao received the 2021 Best Paper Award from the standing committee of the Transportation Research Board (TRB): Economic Development and Land Use.

Professor Cao collaborated on the paper with a team of researchers from Peking University Shenzhen Graduate School. The paper, titled “Nonlinear Effects of Land Use on Metro Ridership in Shenzhen: Implications for TOD Planning,” was led by Qifan Shao, a master's degree student supervised by Assistant Professor Wenjia Zhang and Professor Cao. It was published in the Journal of Transport Geography in December 2020.

The paper received the highest overall rating for presentation at TRB, as well as the highest average of all individual ratings. The committee praised the paper for both its academic rigor as well as for the practical value for land use and transit planners in major cities.

Few studies investigate the nonlinear and moderating relationships between land use and station ridership. Using metro smartcard data in Shenzhen, the team developed a "gradient boosting decision trees" model to estimate the relative importance of land use variables and their threshold and moderating effects on ridership.

The results show that station betweenness centrality has the largest predictive power, followed by employment density and commercial floor area ratio (FAR). The moderating effects suggest that population densification is more effective at terminal stations, whereas the policies intensifying nonresidential use work better at middle stations.

The findings help planners prioritize land use strategies, identify effective ranges of land use metrics, and propose land use guidelines adaptive to the network position of stations.