| It is believed that driving behavior is one of the most important factors impacting vehicle emissions. However, some other factors may also contribute to it indirectly, such as the geometric elements of a roadway. With the increasing application of connected and automated vehicles, however, computers are gradually taking more controls from human drivers, which means that driving patterns will become more similar and easier to identify. Factors such as pavement roughness and roadway geometric elements will likely become more evident in emission with the assumption that a majority of vehicles on the road are automated. The goal of this research is to quantify the environmental impact of horizontal curves on two-lane rural highways through field tests under real-world driving conditions. A series of algorithms and models were developed to examine the linkages among geometric features of horizontal curves, driving behavior and vehicle emissions. The main outputs of this study include an algorithm to calculate curve radius using GPS data, exponential models to estimate critical events using curve radius, and an emission factor table to help roadway designers estimate vehicle emissions for horizontal curves. |
