Embodiments of a method for improving movement characteristic determination using a plurality of mobile devices associated with a vehicle can include: collecting a first movement dataset corresponding to at least one of a first location sensor and a first motion sensor of a first mobile device of the plurality of mobile devices; collecting a second movement dataset corresponding to at least one of a second location sensor and a second motion sensor of a second mobile device of the plurality of mobile devices; determining satisfaction of a device association condition indicative of the first and the second mobile devices as associated with the vehicle, based on the first and the second movement datasets; and after determining the satisfaction of the device association condition, determining a vehicle movement characteristic based on the first and the second movement datasets.