A Study of Flow Characteristics of National Highway

Transport sector plays a very significant role in improving the economic development of any country. Road transportation is the major component of the transport sector in India. India has one of the largest road networks in the world hovering around 3.4 million km at present. As per present estimate, total road network carry nearly 65% of freight and 85% of passenger traffic. Traffic on roads is growing at a rate of 7 to 10% per annum while the vehicle population growth is of the order of 12% per annum. Traffic operation on a two-lane two-way highway is unique. Lane changing and overtaking are possible only in the face of on-coming traffic in the opposing lane. The overtaking demand increases rapidly as traffic volume increases, while passing opportunities in the opposing lane decline as volume increases. Therefore, flow in one direction influences flow in the other direction. The problem is more acute in case of mixed traffic flow when speed differential among different categories of vehicles is quite substantial. Important traffic conditions that affect capacity of a two-lane road are composition of traffic stream, directional split and presence of slow moving vehicles in the stream