Vehicle Emissions at Intersections Before and After Signal Improvement: Zonguldak Example
Emissions of motor vehicles, one of the most important air pollution sources in the city, are emerging as a growing problem in large-scale cities. The amounts of emissions are affected by the number of vehicles in traffic, vehicle technology, geometric and traffic conditions of highways and intersections, environmental factors and driver behaviors. Traffic flow is mostly interrupted at Intersections in local traffic especially at city centers. Emissions of these points, where traffic behavior is changed and vehicles stop and go, are higher as compared to uninterrupted flows. In this study, current state emissions at Zonguldak Intercity Bus Terminal Intersection were determined by SIDRA INTERSECTION software. Then, new emissions are determined by the same software after improvement in signalization. As a result of the study, fuel consumption and pollutant emissions were calculated before and after improvement. As a result of observations at the intersection, current state fuel consumption was calculated as 477.2 l/hour and CO2, CO, HC and NOx emissions were 1229.0, 0.806, 0.126 and 1.212 kg/hour respectively for morning. Then, intersection was modeled again after improvement by changing the cycle time. This leads to 48% reduction in total fuel consumption. In addition, CO2, CO, HC and NOx emissions were reduced by 48%, 56%, 61% and 42% respectively. After that current state fuel consumption was calculated as 545.8 l/hour and CO2, CO, HC and NOx emissions were 1289.1, 0.917, 0.147 and 1.154 kg/hour respectively for the evening. Then, intersection was modeled again after improvement by changing the cycle time. This leads to 45% reduction in total fuel consumption. In addition, CO2, CO, HC and NOx emissions were reduced by 45%, 54%, 57% and 42% respectively. It has been determined that there were significant differences between current state and after improvement. Improvements on geometric conditions or signalization at intersections may result in decrease in vehicle emissions and improving air quality of cities. Keywords: Air Pollution, Motor Vehicle Emissions, SIDRA INTERSECTION, Turkey.