TRAFFIC FLOW AND ENVIRONMENTAL IMPACTS OF FOUR-LANING OF SELECTED MAJOR TRAFFIC CORRIDOR

Abstract

To cope up with the problem of very high volume of traffic coupled with unprecedented levels of traffic densities on major corridors because of high population growth, the developing countries like India are continuously expanding their networks as well as its capacity at the existing systems. Motorised traffic volume has also increased at a alarming rate, causing excessive-environmental degradation and consequent concern. Construction of highway is often 'coupled with environmental degradation . So it is necessary to ensure that any new or improved highway is not only safer and more efficient but also environmentally acceptable. In developed countries, the Environmental Impact Assessment (ETA) has become an integral part of highway planning and design. But in India considerations for environmental impact are still in initial stages. Only during seventy's there has been an awakening in India also that the environment is very severely affected due to vehicular traffic operation. And as a matter of fact, the capital city of India, New Delhi is environmentally ranked as the forth most polluted city of the world. In the present-study an attempt has been made to investigate in detail the traffic related environmental impact of four-laning such as noise and air pollution on the selected highway corridor on NH-2. In all, three locations were selected on NH-2, out of which First was already four-laned, Second on the construction site, where two lanes were blocked for the construction activities and the third on the two-lane highway. (iv) In all the three locations, noise levels and ambient air concentration of pollutants were measured along with the traffic count and traffic speed for 8 hr (9 AM to 5 PM). Traffic count shows that the traffic volume on the four-lane highway increases. Cumulative Distribution curve for the free speed of vehicles shows that median speed is less on the 2 lane highway and 4 lane highway, where two lanes were blocked for the construction activities. Noise level survey carried out at the three locations show that even the minimum noise level was also higher than the maximum recommended limit of 65 dB (A). The maximum noise level was observed at the construction site due to operation of equipments. The results of laboratory analysis for the ambient air quality show that the Suspended Particulate Matter (SPM) was maximum on the construction site. Sulpher dioxide (SO2) and Lead (Pb) were found well within the prescribed limits, Nitrogen Oxide (NOx), was Slightly higher then the prescribed limits, while carbon monoxide (CO) and Hydro carbons (HC) were higher than the permissible limits. The NH-2 is proposed to be four laved from Delhi to Agra. Keeping in view the high noise levels and alarming concentration of pollutants, some traffic engineering and management techniques, such as right of way and geometric improvements to the existing highway should be employed. During construction works to maintain the environmental quality on this highway corridor, some .important recommendation are also given in this thesis.