ENVIRONMENTAL IMPACT OF KANSAS ROUNDABOUTS

With increasing traffic through the years there has also been a considerable increase in vehicular emissions. Problems posed by environmental impacts of traffic are growing and are a challenge to traffic engineers. Modern roundabouts can improve traffic flow as well as cut down vehicular emissions and fuel consumption by reducing the vehicle idle time at intersections, thereby creating a positive impact on the environment. The primary focus of this research is to study the impact of modern roundabouts in Kansas in cutting down vehicular emissions. Three locations in Kansas; namely, Olathe, Lawrence, and Paola, where a modern roundabout replaced a stop controlled intersection, were chosen for the study. The operation of the roadways at the intersection was videotaped and traffic flow data was extracted from these tapes and analyzed using aaSIDRA (Signalized and Un-signalized Intersection Design and Research Aid) software, version 2.0. The software produces many Measures of Effectiveness (MOEs) of which 4 were chosen for analyzing environmental impacts of roundabouts. The chosen 4 MOEs give rate of emission of HC, CO, NOX, and CO2 in (kg/hr). All the MOEs were statistically compared to determine which intersection control performed better. After observing all the MOEs at all locations for the before and after traffic volumes, it was found that the modern roundabout performed better than the existing intersection control (stop signs) in reducing vehicular emissions, thereby resulting in a positive impact on the environment. The paper concludes that modern roundabouts can be considered a viable means of reducing vehicular emissions, thereby making intersections more environmentally friendly.