Investigating the effects of technical parameters of forest road planning and building on traffic noise reduction

This study was conducted to investigate the effect of longitudinal slope, type of surfacing layer, and forest stand status at the edge of the road on traffic noise reduction. Three types of vehicles, including a Land Rover, motorcar, and small truck were selected for this study. Noise intensity was recorded on eight measurement sites with distances of 0, 10, 20, 30, 40, 50, 75, and 100 meters from a forest road in an open area without trees, a pure stand of Alder, and a mixed stand. Results showed that the noise intensity of the Nissan was significantly more than that of Land Rover and Pride. Besides, traffic noise on the dirt road was more than that of the asphalt road. Vehicle noise intensity increased with increasing longitudinal slope of the road. The noise intensity produced by traffic in an open area was more than that in pure stands of Alder and mixed stands. Vehicle noise intensity decreased with increasing distances from the road.