Driving is so routine that we rarely think about the physics behind it, but mass is a big part of how long a vehicle takes to stop. For a loaded service truck full of tools and parts, that increased mass is a major factor in stopping safely.
How Far Does It Take to Stop?
At 55 mph in ideal conditions, a typical car stops in about 225 feet, while a semi takes about 335 feet, and a field service truck is similar. At 65 mph, the car needs about 316 feet and the truck about 525 feet, which is nearly the length of a football field. And that is under ideal conditions, since wet roads, worn or overinflated tires, top-heavy loads, delayed reaction, and distractions all increase stopping distance dramatically.
How Do You Stop Safely?
You do not need to do the math behind the wheel, but keeping it in mind helps. A study found that 90 percent of accidents could have been avoided if the driver had reacted one second earlier, so keep your speed down, look far ahead to increase your warning time, drive defensively, and start braking early.