Dr. Mickey Campbell, recent alumnus and assistant professor at Fort Lewis College, and Geography faculty member Phil Dennison published a paper in the journal Applied Geography on hiking, jogging, and running travel rates derived from crowd-sourced GPS data. Using a massive, crowdsourced fitness-tracking database provided by the online fitness community Strava, they analyzed GPS data from nearly 30,000 people around Salt Lake City, Utah. The individuals hiked, jogged, and ran a combined 81,000 miles, equivalent to more than three trips around the Earth’s equator.
“This will revolutionize our understanding with how terrain affects pedestrian movement,” said Michael Campbell, assistant professor at Fort Lewis College and lead author of the study. “From a firefighter perspective, under normal conditions a fire crew may have ample time to hike to a safety zone, but if the sh*t hits the fan, they’re going to have to sprint to get there. We tried to introduce predictive flexibility that can mimic the range of conditions that one might need to consider when estimating travel rates and times.”
“Calculating how quickly people move through the environment is a problem more than a century old. Having data from such a large number of people moving at all different speeds allowed us to create much more advanced models than what’s been done before,” said Phil Dennison. “Any application that estimates how fast people walk, jog, or run from point A to point B can benefit from this work.”
The most widely used model to estimate travel rates by slope is Tobler’s hiking function. In 1993, geographer Waldo Tobler fit a mathematical function to a figure that summarized empirical data collected in the 1950s, prior to the age of GPS. People have used Tobler’s hiking function to estimate evacuation times for tsunamis, missing person search and rescue and wildland firefighter escape routes. The next most widely used function, called Naismith’s Rule, has been around since 1892. A Scottish mountaineer went on a hike, then wrote an entry in the Scottish Journal of Mountaineering. Based on his personal experience, he wrote that one should budget three hours for every three horizontal miles traveled, and add one hour for every 2,000 vertical feet ascended.
“Hundreds of people are using these slope travel rate functions based on a random Scottish dude from the 1890s and some data from the 1950s,” said Campbell. “We wanted to do better.”
According to the results of the study, a slow walk on a flat, 1-mile (1.6 km) trail takes about 33 minutes on average, whereas that same level of exertion on a steep, 30 degree slope will take about 97 minutes. On the other end of the spectrum, a fast run on a flat, 1-mile trail takes about six minutes, as compared to 13 minutes up a 30 degree slope. People move most rapidly on a slightly downhill slope, and travel rates were faster for downhill than uphill movement. For example, walking down a steep slope of 30 degrees was done at the same speed as walking up a slope of 16 degrees.
Starting this month, the geographers will apply their new models to wildland firefighters. During their spring training, nearly a dozen fire crews in Utah, Idaho, Colorado and California will use GPS trackers to record their movements and log their travel rates. This will allow them to better understand the travel rates of the unique firefighter population, who are often traversing rugged terrain, working long hours, and carrying heavy packs.