Value of Travel Time :Theoretical and Empirical Method

The value of travel time savings (VTTS) is the monetary value attached to save a determined amount of travel time. VTTS is also the most important benefit category aimed at justifying investments in transport infrastructures by public administrations. Hence VTTS played a significant role in various economic studies, both analytical and empirical (Zamparini & Reggiani, 2007). "It is difficult to name a concept more widely used in transportation analysis than the value of travel time. Its theoretical meaning and its empirical measurement are fundamental to travel demand modeling, social cost analysis, pricing decisions, project evaluation, and the evaluation of many public policies".(small,2012) In developing countries the lack of data regarding the economic value of  time savings cause that it often be omitted from appraisal or relied upon proportion of market wage rate (the wage rate method) or using values obtained from developed countries. of course the values obtained from developed countries have serious drawbacks because existing research suggest that value of time is highly affected by preference, physical characteristic of geographical area and habit of particular society ,thus different situation require different modeling and attempt to transfer result from one area to another are fraught of danger, on other hand empirical and  theoretical research indicates that the value of time can be significantly higher or lower than the current wage rate, depending on many condition .This paper uses a revealed preference approach to estimate the VTTS for work and educational trips by collecting 480 questioners from individuals that trip in morning peak time in Isfahan city in 1392, and use of discrete choice model for modeling individuals' preferences. Estimated results show, the value of travel time in Isfahan city in morning peak time is 350.50 Rials for each minute and 21030 Rials for each hour in this year.