Transport policy prioritisation for Dublin

Internalisation of the external costs of transport is currently the subject of much debate. Estimation of costs such as those of pollution and congestion is a primary element in any strategy involving policies for use in the internalisation of these costs. The objective of the TRENEN II STRAN project, funded by the EU, was to develop a methodology for estimation of the marginal external costs of transport. The model developed during the project was used in a series of case studies. One of the case studies, that conducted for Dublin, is reported in this paper. A brief summary of the TRENEN approach is presented followed by the results for Dublin produced from policies such as Do Nothing, Uniform pricing (internalising external costs by means of fuel taxation), Congestion Pricing (cordon pricing) and a first-best policy, the Full Optimum where one assumes that the policy maker has perfect pricing instruments available. As one would expect, the model shows that the greatest reduction in traffic level and external costs would occur if it were possible to introduce a highly differentiated and sophisticated pricing system. Increased taxation on fuel is not an efficient policy as it does not address the marginal external costs of congestion in a way that time-differentiated road-use pricing would. The results from testing of the different measures are interesting particularly those relating to parking and the way in which residents within the CBD and commuters to the CBD are dealt with. This revised version was published online in June 2006 with corrections to the Cover Date.     

Distance and time based road pricing trial in Dublin

The objective of the work was to evaluate the potential user response to distance and time based road pricing of a sample of individuals drawn randomly from a group of volunteers in Dublin. The road use pricing charge levels were selected to match the marginal external costs of car transport i.e. those costs not currently paid by the car user. Such costs include marginal external costs of congestion, air pollution and noise. The project formed part of the EU DGXVII EUROPRICE project where one of the objectives was to evaluate the impact of road use pricing on private transport demand. Estimates of the marginal external costs of car travel had been previously made for Dublin in an EU DGVII project entitled TRENEN II STRAN and the results were used to select the road pricing charges in the trial. The distance travelled and travel time of a particular individual's work trip were noted. Charges per unit distance and time were applied so that the individual would incur a total charge for their average peak period work trip of 6.4 euro; the average marginal external cost of a peak period trip in Dublin, as estimated by the TRENEN model. Although the sample of individuals was relatively small, the indications from the results are worthy of note and further investigation on a larger sample. A significant reduction in the number of peak period trips was evident, of the order of 22%, resulting from trip suppression and transfer to other modes. This revised version was published online in June 2006 with corrections to the Cover Date.