Highway Research Record

VI. RESEARCH WORK DONE IN ACADEMIC INSTITUTIONS RELATED TO THESIS WORK
C. TRAFFIC AND TRANSPORTATION
Development of Capacity Standards for Indian Highways

Date of Start:January 2005
Indian Institute of Technology Madras (R, C)

Scope and Objective
The capacity of highways is affected by various factors. The factors are mainly related to the roadway, traffic and environment. Roadway factors that influence the highway capacity significantly are lane width, shoulder width, gradient and lateral clearance. The important traffic conditions, which have a significant impact on the capacity, are traffic stream composition, and directional split of traffic. Environmental conditions such as urban, rural, day or night also affect the driver behavior and hence capacity. Moreover surface conditions of pavement like wet or dry and roughness can reduce the capacity. Traffic control and regulations such as speed limit, access controls etc. also affect highway capacity. The aim of the research work is to develop the capacity and service volume standards for multilane highways under heterogeneous traffic conditions. The effect of influencing factors on capacity of multilane highways will be taken into account by deriving appropriate adjustment factors for free flow speed under mixed traffic conditions using computer simulation model.

Methodology
The development of capacity and service volume standards involve the following major steps-
(i). Determination of free-flow speed.
(ii). Determination of flow rate.
(iii). Development of relationships between
      a. Speed and flow and
      b. Density and flow.
(iv). Determination of level of service Criteria.