Conference Proceeding
Authors: Johnathon P Ehsani (Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD) , Fearghal O'Brien (School of Business, National College of Ireland Dublin, Ireland) , Bruce Simmons-Morton (Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD)
Due to their widespread adoption, smartphone applications (apps) could allow for a simple, low-cost assessment of driving behavior on a population scale. A number of existing apps are capable of measuring g-forces while driving, but few evaluations have been conducted to determine their accuracy. The goal of this study was to compare the measurement of g-forces between two devices: a custom-built smartphone app and an in-vehicle device that is currently used for research purposes (DAS). The test occurred under experimental conditions on a test track, where a vehicle, equipped with both the DAS and a smartphone with the app installed, performed a number of different acceleration events (e.g. hard-braking, sharp turning, etc.) under controlled conditions. We found that the app captured data that followed the same overall pattern of the DAS, but had a lower amplitude of measurement and a lower signal-to-noise ratio in the data. In general, the strength of the association between the app and DAS improved as the velocity of the events increased (though this was not true for all maneuvers). The correlations between the app and DAS were weaker for other maneuvers, and this may be due to delays in registering the maneuver. These findings indicate that a smartphone application did not register driving maneuvers in the same way that a dedicated in-vehicle device recorded them. Smartphones are ubiquitous and could represent a valuable driving research tool, however steps such as validation and testing are required, before they can be deployed in field trials.
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How to Cite: Ehsani, J. , O'Brien, F. & Simmons-Morton, B. (2017) “Comparing G-Force Measurement Between a Smartphone App and an In-Vehicle Accelerometer”, Driving Assessment Conference. 9(2017). doi: https://doi.org/10.17077/drivingassessment.1639