The Road Less Traveled: Does Rail Transit Matter?
Tao Tao, Jason Cao, and Xinyi Wu, 2021. Journal of Planning Education and Research.
Quantifying the effect of rail transit on vehicular traffic helps policy makers understand its transportation benefits. Previous studies seldom consider the effect over time and the influence of confounding factors. We apply a quasi-experiment research design to explore the evolving impact of the Green Line light rail transit on vehicular traffic in the Twin Cities, controlling for road classification, land use, and transit supply. The results show that rail transit is a substitute for automobile traffic, but induced and diverted trips gradually reduce the substitution effect. The reduced effect suggests that rail transit improves transportation system performance.
Exploring the non-linear associations between spatial attributes and walking distance to transit
Tao Tao, Jueyu Wang, and Jason Cao, 2020. Journal of Transport Geography, 82, 102560.
When examining environmental correlates of walking distance to transit stops, few studies report the importance of spatial attributes relative to other factors. Furthermore, previous studies often assume that they have linear relationships with walking distance. Using the 2016 Transit On Board Survey in the Minneapolis and St. Paul Metropolitan Area, this study adopted the gradient boosting decision trees method to examine the relationships between walking distance and spatial attributes. Results showed that spatial attributes collectively have larger predictive power than other factors. Moreover, they tend to have non-linear associations with walking distance. We further identified the most effective ranges of spatial attributes to guide stop area planning and stop location choice in the region.