【正文】 lem, resulting in greater time delay, increase of energy consumption and air pollution, decrease of reliability of road work. In many cities traffic congestion is seen as a hindrance to economic development. Numerous methods can be used to address congestion and reduce transport density, including building new infrastructure, improving maintenance and operation of infrastructure, and using the existing infrastructure more efficiently through demand management strategies, including pricing mechanisms. Congestion pricing has long been proposed as an effective measure to bat traffic congestion. The principle objective of congestion pricing is to alleviate congestion by implementing surcharge for the use selected congested facilities during peak time periods. By shifting some trips to offpeak periods, to routes away from congested facilities, or to higheroccupancy vehicles, or by discouraging some trips altogether, congestion pricing schemes would result in savings in time and operating costs, improvements in air quality, reductions in energy consumption and improvements in transit productivity. There are lots of successful applications in some countries and regions in the rest of the world. Following Singapore in the early 1970s and Norwegian toll rings in the mid1980s, the city of London introduced its area toll in February 2022。 up till now, it is the most wellknown example of a large metropolitan area that has implemented congestion pricing. However, congestion pricing has not seen widespread use in practice due to theoretical and political reasons. Some potential impacts of road pricing remain unknown, and the sustainability of congestion pricing for urban development requires further study. Sustainability is normally taken as basic objectives in the assessment of transportation policy. The idea of sustainable transportation emerges from the concept of sustainable development in the transport sector and can be defined as follows， “sustainable transportation infrastructure and travel policies that serve multiple goals of economic development, environment stewardship and social equity, have the objective to optimize the use of transportation systems to achieve economic and related social and environment goals, without sacrificing the ability of future generations to achieve the same goals”. Sustainable transportation systems require a dynamic balance between the main pillars of sustainable development, economic development, environmental protection and social justice for current and future generations. In the context of sustainable transport systems, how congestion pricing can contribute to economic growth, environmental protection and social justice is examined in this paper. The rest of the paper is structured as follows. In section 2, the impacts of congestion pricing on economic development are described. Section 3 presents the contribution to environment protection, and the relationship between social justice and congestion pricing is analyzed. Some conclusions are given in section 5. 2. Economic development Traffic congestion, resulting in the increase of travel time, traffic accident, energy consumption and environment deterioration, has produced numerous economic losses. It was reported that economic loss caused by traffic congestion amounted to 40 million Yuan per year in Beijing and 1/3 of GDP in Shanghai in 2022 In many cites, traffic congestion has seen as a hindrance to economic development. Any sustainable transportation management polices should meet the goals of improving the effects of transport on economic development, and without adversely impacting the environment and the potential for further economic growth. How effective would congestion pricing strategy be in reducing congestion, lowering pollutants and greenhouse gas emissions, cutting fuel use, and reducing other adverse impacts of current transportation system? The basic economic principles of congestion pricing can be illustrated in Figure 1. Theoretically, individual users decide whether or not to use a particular road by weighing the costs they will to bear against the benefits to themselves. Total social benefits can be measure by the area under D in Figure 1. The user costs indicated on the MPC curve reflect only the costs borne by each user as new users (. “marginal” users) are added. However, the marginal user occasions additional social costs, such as air pollution and delay to other users, which he does not bear. The total costs borne by each marginal user and the social costs occasioned by him are the marginal social costs of each trip. Marginal social costs are indicated by the MSC curve in figure 1. Figure 1 Effect of congestion pricing If there are n vehicles in the transport system, and mean user cost is represented by MPC, one marginal user added will increase mean user cost to MPC+ △ the marginal social costs can be formulated as MSC = (n + 1)( MPC + ΔMPC ) ? nMPC= MPC + ΔMPC + nΔMPC Congestion pricing is an important means of transportation demand management, and initially only affects transportation decisions. Practices prove that congestion pricing can effectively regulate traffic travel time and space distribution, promote effective utilization of road resources, and enhance the efficiency of transportation operations. Congestion pricing implementation in Singapore has showed that traffic volumes decreased by 17% in peak time periods, and London’s experience also indicated that pricing schemes was successful. As we convert all the savings in travel time resulting from decreased congestion to moary units, we can conclude that the reduction of congestion will promote sustainable economic development. Toll will affect traveler