Road traffic performance monitoring in Beijing

In Beijing, with the rapid growth of motor vehicles, the contradiction between traffic demand and supply becomes more and more serious. Many travel demand measure (TDM) policies have been researched and implemented. The most important measures are "odd-even vehicle ban" during the 2008 Olympics and "vehicle ban one day a week" after the Olympics. Because the traditional traffic flow parameter such as speed, volume or density cannot give a comprehensive and traceable description of the road traffic congestion, a set of urban road traffic performance indices have been put forward. Five comprehensive indices are used to describe traffic congestion from the aspects of intensity, extension, duration, frequency, and reliability respectively. Based on abundant ITS data inputs, Beijing intelligent transportation analysis platform (BTAP) is designed and developed, by which the overall road traffic performance of Beijing especially the urban area with the fifth ring road can be monitored in real-time. The platform plays an important role in transportation policies making, transportation planning and management. Furthermore, the effects of TDM policies have been monitored by the platform. In this paper, the definition and calculation method of road traffic performance indices are introduced, and then the road traffic performance under TDM policies are analyzed comparatively. It is shown that the whole set of indices and methodology are scientific and practical, which explores a new way to monitoring the traffic performance and congestion evaluation in real-time based on ITS data.