Benefit Analysis for an ITS-solution Based on Change in Consumers' Surplus for the Users
Unn Karin Thorenfeldt, SINTEF Transport Research, Dag Bertelsen, SINTEF Transport Research
The paper presents a new method for cost-benefit analysis for calculating the user benefit of having access to travel time information either before or during his travel. The method is based on the travellers stated willingness to changes his travel behaviour given a certain traffic delay on his travel route from home to work or vice versa.
The Norwegian Public Roads Administration (NPRA) is establishing a system (AutoPASS Travel Time System) that presents live travel times for a road section to travelers. The system is already in use on E18 in Oslo Norway. NPRA wanted to complete a cost-benefit analysis of such a system. The section in question Filipstad –Asker has high traffic density during peak hours, often resulting in considerable delay. SINTEF Transport Research was invited to carry out this analysis, which was completed in January 2013.
A user survey was answered by several groups of travellers. The survey collected information on the travellers normal travel time and the delay that would result in a change of travel behaviour. A concrete question on the road users' willingness to pay for the information service did not give a reliable answer to their benefits, as anticipated. Therefore the benefit from real travel time information had to be analysed in another way. Compared to the AutoPASS system measured delays the travelers' estimation was very accurate.
In one of the questions in the survey, the road users were asked to state a critical level of delay causing a change in their behaviour, for example stay home, change the time for travel start or change travel route. Traffic delay normally means a reduction in consumers' surplus for the users of the road. To some extent travel time information allows the users to compensate for the reduction in consumers' surplus due to traffic delay.
The AutoPASS-system collects and delivers continuous data of the real time delay. This information tells us how often the travelers limit for changing travel behaviour is exceeded within the period of evaluation.
Each traveler has a unique normal travel time and a critical delay that will cause change in travel behaviour. To make up for the difference in distance of travel the normal travel time was taken in to consideration. Information from each traveler in the survey was used to make a downward sloping demand curve. Using the method of consumers' surplus the benefit from receiving information on travel time can be calculated. Such calculations were performed for one month in the autumn of 2012. The result from the calculations represents the benefit of not loosing time in traffic.
The results from the evaluation from the section on E18 in Oslo Norway proved to be higher than the investment which means that the investment in the travel information system was right for society.
A more detailed description of the method and the results of the calculations for the road section in question will be presented in the paper.
Association for European Transport