EFFECT OF ROADSIDE PLANTING AND ROAD STRUCTURE ON NO2 CONCENTRATION NEAR ROAD

The role of a roadside buffer planting belt and road structure in controlling air pollutants was studied by determining the distribution of NO2 in open fields and planting areas near roads of various structure. NO2 concentration was found to decrease with distance from the road, but the reduction in planting sites was greater than in open fields. Roadside planting at a level road structure was found to reduce NO2 concentration by 3.5 ppb at 10 m and by 2.3 ppb at 150 m from the road. Road structure influenced NO2 concentration 5 m from the road; the concentration decreased as height of the road noise barrier increased, and this effect was enhanced by the presence of a planting area at all structures except the bank road.