The Urban Traffic Travel Time Volatility Value Evaluation Research

With the accelerated process of urbanization and the improvement of quality of life, more attention is paid on travel time reliability, thus travel time reliability is becoming more and more important. Usually, it’s distinguished by travel time reliability value. After a systematic analysis of the influence, causes, classifications and representations of travel time variability, a description and evaluation method is proposed. Cloud model is used to evaluate travel time variability based on its advantages to solve the randomness and fuzziness of a problem. Travel time variability is introduced into the model as a qualitative value, then a travel time variability assessment model of urban transportation system is established. In this model, travel time, travel cost and travel time variability are considered. The use of cloud model is to converse travel time variability into quantitative value. At this time, survey requirement, survey questionnaire design and survey implement are discussed, orthogonal design method is introduced, database is applied in SP survey questionnaire design and graphical design based on the normal distribution of travel time fluctuations, the method of combining computer surveys and online survey is used. Using actual data, travel time variability value of urban transportation system is obtained, under different income levels and different travel purposes, and also some useful conclusions. Finally, this method is of great significance in traffic system assessment, traffic model and other aspects. An example is introduced to illustrate its application.