Abstract

The objective of this paper is to provide a brief review on travel time reliability approaches, to explore the relation between reliability and the volume-capacity ratio (saturation level) based on a case study of Budapest, and considering the results to propose an adequate method, plus draft further research. In this paper reliability is analysed based on automatic measurements of journey times and traffic volumes from a dataset for the city of Budapest. Due to the limitations of measurements and data route-level analyses has been carried out. The main finding and the novelty of the study is a model which can forecast the standard deviation of travel times based on the volume-capacity ratio and the free-flow travel time. The results prove that besides existing mean-delay-based models, travel time reliability can be forecasted based on the volume-capacity ratio with an adequate accuracy.