Title: Using GPS data to detect critical events in motorcycle rider behaviour
Authors: Salvatore Cafiso; Alessandro Di Graziano; Oliver Giudice; Giuseppina Pappalardo
Addresses: Department of Civil and Environmental Engineering, University of Catania, Viale Andrea Doria 6, I-95125 Catania, Italy ' Department of Civil and Environmental Engineering, University of Catania, Viale Andrea Doria 6, I-95125 Catania, Italy ' Department of Mathematics and Computer Science, University of Catania, Viale Andrea Doria 6, I-95125 Catania, Italy ' Department of Civil and Environmental Engineering, University of Catania, Viale Andrea Doria 6, I-95125 Catania, Italy
Abstract: A relevant research issue in naturalistic studies is related to analysis and evaluation of the huge data recorded during the experiment. A procedure to identify critical events of PTW is presented and tested using parameters measured or derived by GPS. Raw measures of speed, position and time are copied directly from the data string stored by the GPS in National Marine Electronics Association (NMEA) protocol. From these other measures useful in explaining the rider behaviour were derived. Smoothing cubic spline and Butterworth filters were used to improve the estimation of measures effected by GPS inaccuracy. The Mahalanobis distance was adopted to identify multivariable outliers for each combination of raw and derived measures. The events classified by Mahalanobis distance as outliers from the 'normal' rider behaviour were compared with the critical traffic conflicts self-reported by the rider during the experimental test in order to evaluate recall and precision of the method.
Keywords: naturalistic study; motorcycles; motorbikes; motorcycle speed; motorcycle position; video; digital cameras; Mahalanobis distance; time; smoothing cubic spline; Butterworth filters; multivariable outliers; GPS data; global positioning system; critical events; motorcycle riders; rider behaviour; powered two-wheelers; PTWs; motorcycle crashes; near crashes; normal driving conditions.
DOI: 10.1504/IJMNDI.2014.067182
International Journal of Mobile Network Design and Innovation, 2014 Vol.5 No.4, pp.195 - 204
Received: 20 Feb 2014
Accepted: 16 Jul 2014
Published online: 07 Feb 2015 *