The measurement target was the joint angles of an athlete performing a BMX Supercross (SX) gate start action through the first 1.2 s of movement in situ on a BMX SX ramp using a standard gate start procedure. N2 - The aim of this study was to quantify the validity and intra-tester reliability of a novel method of kinematic measurement. T1 - The validity and intra-tester reliability of markerless motion capture to analyse kinematics of the BMX Supercross gate start The methodology is valid within 2° and reliable within 6° for the calculation of joint angles in the first ~1.25 s.", Intra-tester reliability was high, with an absolute error <6° and <9 frames (0.075 s) across all angles and time points for key positions, respectively. Intra-tester reliability was measured by the same tester performing the analysis twice with an average of 55 days between analyses. The gold standard 3D method for joint angle measurement could not safely be employed in this environment, so a rigid angle was used. The methodology is valid within 2° and reliable within 6° for the calculation of joint angles in the first ~1.25 s.Ībstract = "The aim of this study was to quantify the validity and intra-tester reliability of a novel method of kinematic measurement. Tracking data was exported and angles computed in Matlab (Mathworks®, USA). Kinovea 0.8.15 (, France) was used for analysis. The method employed GoPro® Hero 4 Silver (GoPro Inc., USA) cameras capturing data at 120 fps 720 p on a 'normal' lens setting. For this study, data has been collected from different median openings located on six-lane divided urban roads.The aim of this study was to quantify the validity and intra-tester reliability of a novel method of kinematic measurement. Finally clustering technique has been used to define various severity indices for probable road crashes at median opening area. A critical safe ratio has been introduced to better analyze the traffic safety at median opening based on minimum stopping sight distance (SSD) as per IRC: 66–1976 and speed to PET ratio. Therefore, in this study, PET across different traffic volume levels at median opening area is calculated. Among all the traffic safety measures, PET is regarded as the most reliable and most commonly used indicator. These values are based on the temporal and spatial proximity between road-users during possible conflict situation. Various surrogate traffic measures like Deceleration Time (DT), Time to Collision (TTC), Post Encroachment Time (PET), etc. Therefore, in the recent times surrogate traffic safety measures are being used to analyze traffic safety. The accuracy of these accident data details is highly questionable. In developing countries like India, available accident data are based on reports submitted by the police department of respective state governments.
However, the drawback of this traditional method is that a lot of accidents need to be recorded for analysis and to draw any conclusions and take necessary corrective measures. Conventionally, road crash data reports were used to study and analyze traffic safety.
This is due to the fact that neither lane discipline nor priority rule is followed at the median openings. Moreover, at median openings which are usually uncontrolled in India, the severity of road crashes increase many fold. In a developing country like India, it is observed that in every four second, one person gets injured in road crashes. Traffic safety assessment is an integral part of transportation engineering.