Free Speed Modeling for Urban Arterials - A Case Study on Delhi


  • Amudapuram Mohan Rao

    Central Road Research Institute, New Delhi 110 020

  • K Ramachandra Rao

    Department of Civil Engineering Indian Institute of Technology Delhi Hauz Khas New Delhi-110016 India


Free-flow speed is an important characteristic for capacity and level-of-service analysis of urban arterials. The objective of this study is to develop models for estimating free-flow speed. Many generic factors like weather, environment, vehicles, roadway characteristics, driver and traffic streams either singly or in combination influence the free flow speed. The quantitative measures of these factors are desirable for reliable free flow speed measurement and system design. In this paper an attempt has been made to identify the factors which affect the free flow speed. Data collection was done on the midblock segments of urban arterials in Delhi. Further, the geometric properties of the arterial were collected by dividing the given stretch of the road into smaller segments. The factors such as, total number of vehicles, major intersections, access points and length of the sections seem to have a significant influence on free flow speeds.



Free speed; friction factors; traffic flow characteristics; data processing

Published Online


How to Cite

Rao, A. M., Rao, K. R. (2015) “Free Speed Modeling for Urban Arterials - A Case Study on Delhi”, Periodica Polytechnica Transportation Engineering, 43(3), pp. 111–119.