Skip to main content

Bike Crash Wiped Details; GPS Data Filled Them In

By September 5, 2011October 17th, 2021No Comments

The New York Times: Bike Crash Wiped Details; GPS Data Filled Them In

Published: September 5, 2011

WOODSIDE, Calif. — After racing and biking back roads on the San Francisco Peninsula for almost half a century without serious incident, on July 3 I crashed while riding downhill at more than 30 miles an hour. I knocked myself out, broke my nose and was left with lots of road rash and stitches on my face, as well as a deep gash above my knee that went all the way to the patella.

But when the paramedics picked me up and sent me to the hospital, I found that the worst thing I had sustained was a hole in my memory, lasting about 20 minutes. I had been riding by myself, and I had no idea what led me to crash.

I might have hit a pothole and been thrown off my bike. Worse, I might have passed out before crashing, a possible sign of a serious underlying condition.

What I do remember is this: Riding back from the Pacific Ocean after a long climb on a hot day, I started downhill. Some time later, I recall coming to, staring up at redwoods.

According to Brian, one of the paramedics who picked me up and put me on a stretcher, I was “A and O times 3,” or alert and oriented in my responses to three standard questions: I knew who I was, where I was and what time it was.

“A and O times 4” would have been preferable. The fourth question, the one I couldn’t answer, was how I got there.

Several days later, while watching the Tour de France from the comfort of my couch, I found I could relate to the American cyclist Chris Horner — who, after finishing a stage despite a concussion, turned to his coach and asked: “I crashed? I finished?”

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.

Late last year Ryan Sabga, another top American bike racer, was hit by a car while crossing an intersection in Denver at the beginning of a training ride. The driver, coming out of an alley, was looking over her right shoulder; she stepped on the gas and made a left turn directly into Mr. Sabga as he reached the middle of the street.

“I yelled as she hit the gas harder and drove right into me,” he wrote in a blog he keeps for his racing team, Black Dog Professional Cycling. “She still didn’t see me.

“Somehow, I did a sort of madison throw” — an extended-arm maneuver — “off the hood of her car and got clipped on my left leg as I launched off. I was badly off balance and then crashed hard on my right side on the side of the road.”

The driver told the police she didn’t think she had hit Mr. Sabga. Though her car had a telltale dent, the officer said that without proof of where the cyclist had entered the intersection, he would not be able to write a citation against the driver. That meant Mr. Sabga, who was relatively unscathed, would not be able to get her insurance company to cover the damage to his bike, which was now in pieces.

Back at home, he realized that he might have the proof he needed in the data stored in the Garmin GPS device he used for training.

“Clear as day, you could see where I stopped at the stop sign, where I got hit by the car and where my bike came to rest,” he wrote. “On the corresponding time stamp, you could see the speeds, the stops and even where my heart rate spiked as she hit me.”

The police were unwilling to pursue the case, but they suggested that he send the data to the driver’s insurance company. He did so within a day, and the company took responsibility for the accident.

Lawyers who specialize in bicycle accidents say GPS data can be used by both sides.

“It’s a double-edge sword,” said James B. Reed of the Ziff Law Firm in Elmira, N.Y., who often represents cyclists involved in collisions with cars. He noted that GPS technology was altering the way both car and bicycle accident claims are settled.

“It’s important for people who are representing the injured people or the insurance companies to know how to obtain and analyze the data,” he said. “Frankly, it’s probably going to be a booming new industry for experts.”

My own GPS data was revealing. For years I’ve ridden with a Garmin 305, a cycle computer that sells for several hundred dollars and records your location and speed as well as heart rate and pedaling rate.

After each ride, a cyclist can upload the data to one of a number of software applications or to a Web service, which will map rides and compare them with previous efforts or those of other riders on the same route.

Strava, the service I use now, makes it possible to sort by age brackets — which always gives me some hope, since as I get older my ranking can still improve even if my performance doesn’t.

My Garmin was unharmed, and when I uploaded the data I could see that in the roughly eight seconds before I crashed, my speed went from 30 to 10 miles per hour — and then 0 —while my heart rate stayed a constant 126. By entering the GPS data into Google Maps, I could see just where I crashed.

I realized I did have several disconnected memories. One was of my hands being thrown off the handlebars violently, but I had no sense of where I was when it happened. With a friend, Bill Duvall, who many years ago also raced for the local bike club Pedali Alpini, I went back to the spot.

La Honda Road cuts a steep and curving path through the redwoods. Just above where the GPS data said I crashed, we could see a long, thin, deep pothole. (It was even visible in Google’s street view.) If my tire hit that, it could easily have taken me down.

I also had a fleeting recollection of my mangled dark glasses, and on the side of the road I stooped and picked up one of the lenses, which was deeply scratched.

From the swift deceleration, I deduced that when my hands were thrown from the handlebars, I must have managed to reach my brakes again in time to slow down before I fell. My right hand was pinned under the brake lever when I hit the ground, causing the nasty road rash.

In recent years, my biggest fear as a cyclist has been of distracted drivers reading e-mail or sending text messages on curvy mountain roads. So much for that: When I finally had a wipeout, it was solo.

There was a silver lining. If you’re a cyclist, the best time to spend recovering from a fall is early July. I was able to spend two weeks getting up early each morning and watching one of the most exciting Tours de France in years.