New measuring method for ride comfort in transit vehicles

This paper presents the results of ride comfort analysis performed on the Morgantown People Mover system and a comparison of results of measurements for other modern transit vehicles. All ride comfort measurements were performed, employing the new Ride Comfort Meter Type II developed and built by Delft University of Technology in Holland. Principals of several ride comfort criteria in use are presented and compared. The proposed criterion of exposure duration for givem vibration levels by the International Organization for Standardization (ISO) were selected for ride comfort measurements. The portable Ride Comfort Meter provides single value measurements which correspond to ISO weighted RMS values of effective accelerations. Each measurement takes 15 seconds and is called the Ride Index (RI). Statistical methods were used to analyze the ride comfort data obtained. Resultant statistical means for vertical and lateral Ride Indices versus vehicle speeds in guideway curves and on straight sections are shown. Linear regression using all data points yielded Ride Index equations for describing the relation of vertical and lateral Ride Index to vehicle speed. Results of ride comfort are shown as the percentage of trip time which the vertical and lateral Ride Indices were exceeded. The ISO reduced comfort boundary is used as a basis to assess the comfort levels encountered at the Morgantown People Mover system. To provide a basis for comparison between the Morgantown system and other transit systems, additional ride comfort measurements were made at three other automated guideway systems and five conventional transit systems.