Geographers use big data to predict how slope affects human travel rates

Have you ever been running on a sidewalk making pretty good time, then hit a hill and slowed way down? If so, you’ve experienced how slope affects travel rates. For most of us, understanding how slope steepness impacts our speed is a matter of fitness. For others, such as wildland firefighters retreating from the fire line to a safety zone, predicting how long it takes to move across terrain can be a matter of life and death.