Unraveling roundabout dynamics: Analysis of driving behavior, vehicle performance, and exhaust emissions
Paulo Fernandes, Elisabete Ferreira, Eloísa Macedo, Margarida C. Coelho
Abstract
This paper examined driving behavior, vehicle operational performance, and exhaust emissions data at a roundabout level. The relative positive acceleration, power demand, speed, acceleration, vehicular jerk, Vehicle Specific Power modes, mass carbon dioxide and nitrogen oxide emissions were evaluated by roundabout type (single-lane, compact two-lane, and multi-lane) and sub-segment (downstream, circulating area, and upstream). Real-world vehicle tailpipe emissions, internally observable variables, dynamic and location data were measured along six conventional roundabouts in Portugal (1 Hz resolution). Although the multilane roundabout yielded the lowest amounts of carbon dioxide, it resulted in highly volatile behaviors based on vehicular jerk thresholds. The emission hotspots were found downstream roundabouts while drivers tend to adopt highly volatile behaviors close to the circulatory roadway. This paper brings valuable knowledge to researchers and transportation practitioners, who are involved in intersection design and control strategies, about the impacts of roundabout design and location based on several criteria.