In the NYT, John Markoff tells a personal story of how GPS data helped him fill in details of a bike crash lost to memory:
While I healed, I became obsessed with figuring out why I had crashed. Hitting a pothole hidden by the afternoon light filtering through the redwoods was one thing. But if I had some weird seizure or heart arrhythmia that led to my passing out, that would be spooky.
What troubled me most was that I had road rash on the backs of both hands. That seemed unusual. Commonly, riders put a hand out to cushion a fall (often breaking a collarbone in the process). Apparently I came down face first.
My helmet had a deep skid mark that rubbed away the shell all the way down to the foam. My bike was also something of a mystery. Beyond torn handlebar tape and brake hoods, it was virtually undamaged. The wheels were true, the fork and frame were untouched.
Ultimately, I was able to put the puzzle together with the cyclist's equivalent of a black box: the digital record of my speed, location, pedal rate and heart rate that was stored in the Garmin cyclometer on my handlebars. I also learned that other cyclists involved in accidents have been able to use similar data to prove what happened in their crashes.
Read the full story here.