Exploring the Effects of Built Environment on Traffic Microcirculation Performance Using XGBoost Model

As the rapid motorization worldwide, the urban issue of traffic congestion continues to deteriorate. Among the solutions to address the traffic congestions issue, making full use of urban microcirculation roads so as to divert the traffic volume from main roads has been recognized as an efficient approach. However, few studies have explored what built environment determinants can affect the microcirculation performance and how do they correlate. By taking the central urban area in Tianjin, China, as a case study, his study aims to explore the nonlinear effect of urban built environment on the traffic microcirculation performance by using XGBoost model. The results show that it is observed with two troughs in traffic microcirculation performance by hours of a day, corresponding to the morning peak around 7:20–8:40am and evening peak around 16:00–19:00pm, respectively. Additionally, crossroad density is overwhelmingly dominant that affect the microcirculation performance, with an overall contribution approximately 40%. Moreover, one-way street, high-rise residential allocation, and T-intersection density are also the key determinants that contribute to the traffic microcirculation performance. Furthermore, most of the important built environment elements show a nonlinear relationship with the efficiency of traffic microcirculation, with slight difference between peak hours and off-peak hours. These findings can be used to collectively guide the local government to reasonably allocate the built environment elements so as to alleviate the traffic congestions.