Quantifying the Accuracy of Detecting Lateral Movement Onset for a Selection of Bicycle GPS Computers

Bicycle computers and apps record, at minimum, positional data over time, and this data is commonly used in accident reconstruction to inform the behavior of the bicycle and rider prior to an incident in question. This positional data is primarily calculated using the Global Positioning System (GPS) and thus specific accuracy and precision is not well quantified. To improve this understanding when it comes to relative accuracy of lateral movements, a series of controlled tests were performed and recorded with several commercially available bicycle GPS computers and apps and compared against a RaceLogic VBox 3i ADAS with Real-Time Kinematic corrections from a RaceLogic Base Station. The testing consisted of 5 sets of 15 runs: 15 runs riding down the center of a lane, 15 making a 6 ft lateral left movement, 15 making 12 ft lateral left movements, 15 making 6 ft lateral right movements, and 15 making 12 ft lateral right movements. Each test run was ended with hard braking to a stop to serve as the reference time and location for all data. Mean error and standard deviations for both the timing of the lateral movements – i.e. time prior to stop of lateral movement onset, time prior to stop of lateral movement end, and total duration of lateral movement – and the locations of the lateral movements – distance from stop of lateral movement onset, distance from stop of lateral movement end, and total distance of lateral movement - were calculated for each bicycle GPS data source.