Traffic Management on Two-Lane Rural Highways

Increasing the width of roads by providing additional lanes is an effective strategy to manage the increase in peak-hour traffic. In this context, the present study aims at forming an association between carriageway width and capacity for two-lane rural highways. The study conducted at 10 different sections of National and State Highways in Kerala had carriageway widths ranging from 6.7 to 9.1 meter under mixed traffic conditions and considered 5 vehicle types. Traffic data were collected using video recording technique, and the speed and flow values were obtained by analyzing the recorded video. A Green Shield's macroscopic stream model was then used to develop the fundamental traffic flow relations. Using these relationships, speed-flow curves were plotted and capacity of each section was found out. A second degree equation between width and capacity was derived, and it was observed that carriageway width had significant positive impact on the capacity of the road. It was concluded that increasing road width is a valuable method to reduce congestion by increasing the capacity and subsequently reducing the travel time. Further, the model developed in the current study predicted a lesser capacity compared with previous studies, and this might be an indicator of the influence of higher side friction on the traffic flow.