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Mobility Optimization: Permits for Emissions from Driving

Final Report Summary - MOPED (Mobility Optimization: Permits for Emissions from Driving)

Road congestion and vehicle emissions have increasing negative impacts on society, environment and economy as a whole. A large body of evidences suggest that the current trends are not sustainable without effective travel demand management. Without new policies, all countries will have to confront a series of traffic congestion and air pollution problems caused principally by the unrestricted use of private cars. In the MOPED project, we have focused on the tradable credits scheme (TCS), researching the potential of this scheme in managing the demand for travel and reducing congestion and emissions. We have compared TCS with road pricing measures and investigated some combined measures to improve transport network mobility.

Most research to date has focused on the use of TCS to manage the related problem of air pollution, but it is clear there is potential to design a scheme for traffic congestion management. We have firstly investigated the evidence and past research on tradable credit schemes and then have focused on their role in road traffic congestion management. We have examined how the travel mode and travel pattern of travelers are influenced by a given tradable credits scheme. An analysis framework has been proposed to investigate the effects of a basic tradable credits scheme. Using a simulation analysis and case study from the Beijing municipality, we have demonstrated that a tradable credits scheme can achieve a target for reducing the expected number of car trips. The research demonstrates that a tradable credits scheme will have an effect on travelers’ mode choice. However, it is likely to have only a minor effect on the overall travel pattern in terms of OD movements.

Using a linear expenditure system (LES) approach, we have investigated the influences of a tradable credits scheme on the pattern of daily trips measured in kilometres. Generally, we assumed that an individuals’ travel consists of a car mode and a non-car mode. The effects of the tradable credits scheme were considered from a microeconomic perspective and using a scenario simulation study for the municipality of Beijing. Whilst other research has shown that travellers trade their credits and are generally inclined to non-car mode, the implementation of the tradable credits scheme demonstrated here is that travellers are likely to restrain their use of both car and non-car travel modes. Furthermore, both car and non-car mode trips are shown to be price inelastic, whilst the cross-price elasticity for different districts demonstrates a complementary relationship between car and bus modes.

We have investigated the influence of a TCS on travel demand and vehicle emissions, based on the vehicle miles travelled (VMT). With a microeconomic quantitative analysis scheme, a constant elasticity of substitution function was used to model the annual mileage for different travel purposes. An illustration is given for the effects of a TCS on emission mitigation based on historical data for Great Britain. A scenario analysis has demonstrated that a tradable credits scheme can achieve a target for reducing the number of private trips. Besides shifting private car trips to public modes, there is also evidence of individuals choosing not to take some trips. The research illustrates that a TCS could have similar effects to a road pricing scheme and that a TCS could bring emission changes arising from changes in VMT.

This project has opened many avenues for further study, created long term collaborations and a mutually beneficial cooperation between Europe and China and strengthened existing relationships. The need for innovative information and communication technologies to implement TCS in the long term should bring potential public private partnerships in support of industrial competitiveness, provide a sustainable transport development patterns, respond to the mobility needs of citizens and support transport policy development.