Environmental Impact of Kansas Roundabouts

With the increase in traffic over the years there has also been a considerable increase in vehicular emissions. Problems posed by environmental impact of traffic are growing and are posing 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 and 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 has replaced a stop controlled intersection, have been 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 four were chosen for analyzing the environmental impact of roundabouts. The chosen four 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 (i.e. stop signs) in cutting down vehicular emissions, thereby resulting in a positive impact on the environment. The research concludes that a modern roundabout can be considered, a viable alternative to cut down vehicular emissions and thereby making intersections more environment friendly.