Evaluating Shanghai's non-local vehicle restriction policy using the empirical macroscopic fundamental diagram

To alleviate traffic congestion in the city center, many cities in China restrict non-local vehicles using expressways or entering the central area during the morning peak and the evening peak, such as Shanghai, Beijing and Shenzhen. In Shanghai, the non-local plate vehicle restriction policy started to be implemented in 2002, which banned vehicles without local plates using elevated highways in the central area from 7:30 am to 9:30 am and from 4:30 pm to 6:30 pm. This restriction was firstly tightened in 2015 and further tightened in 2016, with longer restricted hours and expanded banned expressways. However, no relevant research has been found to empirically evaluate these policies from the perspective of macroscopic traffic performance. In this study, the macroscopic fundamental diagram (MFD) approach is used to evaluate the performances of Shanghai’s macroscopic traffic under the three different restriction policies. The macroscopic effects of the restriction policy on the restricted expressways are compared with the surface roads without any restrictions. Moreover, the time-varying characteristics of macroscopic traffic performance, e.g., hysteresis loop, during the morning peak and the evening peak, are further investigated in this study