Study of travel time variability using two-wheeler probe data – an Indian experience

The objective of this study is to examine travel time reliability under the heterogeneous traffic conditions prevailing in developing countries such as India. The study is carried out using a motorised two-wheeler, which is a dominant vehicular type in conditions such as are found in India on urban arterial roads. Eight runs are conducted during morning peak hours by driving a motorised two-wheeler mounted with a performance box (equipped with high-precision global positioning system) with the traffic stream on the test route between Athwa and Piplod, in Surat city, Gujarat, situated in the western part of India. One of the major outcomes of the study is to propose the most suitable relationships between buffer time index (BTI) and volume-demand-to-capacity (V/C) ratio, as well as between planning time index (PTI) and V/C ratio. From the results, it is found that a polynomial function-based model can predict BTI as well as PTI for the given V/C ratio more accurately. The study also highlights the development of a methodology to define the level of service of a roadway facility based on travel time reliability measures. Furthermore, this research work discusses potential reliability measures for capturing travel time variations more appropriately.