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 2003 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 (i.e. “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+ △ MPC.Thus 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 monetary units, we can conclude that the reduction of congestion will promote sustainable economic development.
Toll will affect travelers’ budget constraints and will result not only in mode switching but also in broader changes in the economy that will be accompanied by the geographic redistribution of trips. Some concerns that congestion pricing may have negative effects on the economy of the central area, particularly on retail. A counterargument, however, states that the reduced congestion is supposed to lower the
costs of the downtown businesses, making them more competitive. The location of retail activity, on the other hand, is also driven by individuals’ preferred shopping locations. As well known, individuals tend to shop near their place of residence, so retail firms cannot easily move out of the core area, because so many people live in center area. This dependence on customer convenience explains why retail production decreases less than the output of other primary industries in the core area. Congestion pricing reduces congestion during the peak time and increases congestion during other periods. By shifting toward public transit and high occupancy vehicles, congestion pricing reduced the number of trips to the pricing areas across all time periods. Except reduced congestion, if improvement of air quality and decrease of fuel consumption are taken into account, the economic efficiency resulting from congestion pricing would be considerable. 3. Environmental protection
In China, environmental problem become increasingly serious. It was reported that china is the second emitter of CO2, and 7 cities are in the list of seriously-polluted cities in the world.
The environmental effects of transportation cover a wide range of different impacts, including for example air pollution, noise, and climate change. Motor vehicles are the dominant producers of urban air and noise pollution, including carbon monoxide, oxides of nitrogen, and airborne particulates. These pollutants are key factors in many respiratory ailments such as asthma as well as “a range of other human health effects, from headaches and eye irritation to cancer”.
The World Bank estimates that 0.5 million people in developing countries die each year from transport-related air emissions, with a similar death toll from traffic accidents.
Transportation cannot be replaced because it is the part of the production chain. For this reason, transportation systems must be developed and standardized, the effectiveness of transportation service must be increased, while the environmental pollution must be decreased or prevented.
Emission from road traffic is a complex system with an output that cannot be
completely measured. It is natural to analyze the emissions from a sample of vehicles under different driving conditions. The California Air Resources Board pointes out that congestion-stop and go traffic significantly increases emissions. As an example, one report estimates that a 10-mile trip, using an average 1987 automobile, results in running exhaust HC emission of 1grams at a speed of 55 mph but that HC emissions would be 7 grams at an average speed of 20 mph, typical of stop-and-go conditions
With respect to air quality impacts, congestion pricing can be expected to improve air quality in two ways. The first impact comes from the reduced level of congestion on the facility, compared with the level of congestion on the un-priced road. The second impact on emissions is due to the reduced number of vehicles on the road facilities. To the extent that higher prices succeed in reducing vehicle miles traveled, there will be fewer vehicles on the road.
It is clear that reduced travel demand in peak periods reflects fewer and shorter trips being made and results in higher travel speeds during peak periods, with consequent reductions in vehicles emissions during peak periods. However, the bulk of daily travel occurring in off-peak periods may be negatively affected, as some peak travelers shift their time of travel to off-peak periods to avoid tolls. Overall beneficial impacts on air quality may thus be smaller than that suggested simply by peak period travel demand reductions. This reduction cannot be measured directly, but will have to be calculated from the information on traffic diversion, congestion reduction, and ride-sharing increase.
In the long term, congestion pricing could lead to increases in use of alternative travel modes for all daily trips, thus reducing total daily emissions. 4. Social justice
Sustainable development has three widely agreed meta-goals: sustainable economic development, environmental protection and social justice. All three goals must be addressed together if development is to be sustainable. Much attention has been paid to economic development and environmental protection, but less attention has been paid to social justice. Social justice (equity) contains economic equity and environmental equity.
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