Vehicle swept path analysis based on GPS data

Vehicle swept path analysis presents an essential step while working on at-grade intersection and roundabout designs. Following the intensive development of computer-aided design (CAD) software in the past two decades, numerous CAD-based computer programs for vehicle movement simulation have been developed and commercially distributed. The accuracy of these simulation programs is usually verified by conducting experimental field tests in which real movement trajectories of design vehicles, equipped with global positioning system (GPS) receivers, are recorded. This paper proposes an improved methodology for retrieving vehicle movement trajectories from collected GPS data. The proposed methodology reduces the trajectory inaccuracy resulting from pavement grading characteristics and the inability to accurately install GPS receivers in relation to streamlined vehicle body. Results of field experiments show that the reduction of positioning errors in the horizontal projection is not smaller than 50.0 mm compared with previous studies.