Developing a reliable estimate for value of time for transportation projects

Value of Time (VOT) is a key parameter used to quantify the economic benefits of travel time savings due to transportation infrastructure development projects. Different methods are used to estimate VOT which depends on factors such as income, trip purpose and trip duration. Simple and accurate method for estimating VOT is necessary especially for developing countries where detailed information is not available. In Sri Lanka, VOT has not been updated for long period due to several reasons, where lack of information and identification of an appropriate method being one of the main reasons Therefore, there is a need to estimate the VOT and a simple but accurate enough methodology is proposed to frequently update VOT estimate based on current economic and social conditions. The methodology has been developed consisting of 3 pronged approach to calculate the VOT and in order to verify the developed methodology, a case study was carried out. As for the first approach, Gross Domestic Product (GDP) has been used to obtain a general value for the VOT of an average person. A willingness to pay survey has also been conducted using a sample of 3,317 vehicle users to obtain a base value for the minimum VOT of a person for non-work based trips. A more detailed analysis was also conducted using the income based approach. Five user categories were taken into account, namely the car passengers, SUV passengers, van passengers, bus passengers and motorcycle / three wheeler passengers. Different VOT values were obtained for each category varying from Rs.528/hr ($3.52) to Rs.188/h ($1.25) highest for SUV users and lowest for public transport users. In order to update the VOT for future periods, it was found that Colombo Consumers Price Index (CCPI) is directly co-related with VOT inflations over the past decades and can be used as an index to update VOT.