Home SCIENCE Why Don’t Roller Coasters Fly Off the Tracks?

Why Don’t Roller Coasters Fly Off the Tracks?

Have you ever wondered how roller coasters stay on their tracks and why people can hang upside down in them? It’s all a matter of physics: energy, inertia, and gravity.A roller coaster does not have an engine to generate energy. The climb up the first hill is accomplished by a lift or cable that pulls the train up.

image credit: Science Channel

This builds up a supply of potential energy that will be used to go down the hill as the train is pulled by gravity. Then, all of that stored energy is released as kinetic energy which is what will get the train to go up the next hill. So, as the train travels up and down hills, its motion is constantly shifting between potential and kinetic energy.

image credit: Science Channel

There are certain features on the wheels of wooden roller-coaster cars to ensure that the roller coaster does not flip over.Upstop wheels apply friction under the tracks to prevent roller coasters from derailing during zero-G drops and turns.


The higher the hill the coaster is coming down, the more kinetic energy is available to push the cars up the next hill, and the faster the train will go. Plus, according to Newton’s First Law of Motion, “an object in motion tends to stay in motion, unless another force acts against it.”

Wind resistance or the wheels along the track are forces that work to slow down the train. So toward the end of the ride, the hills tend to be lower because the coaster has less energy to get up them.The two major types of roller coasters are wooden and steel. Features in the wheel design prevent the cars from flipping off the track.

Wooden tracks are more inflexible than steel, so usually don’t have such complex loops that might flip passengers upside down. In the 1950s tubular steel tracks were introduced. The train’s nylon or polyurethane wheels run along the top, bottom, and side of the tube, securing the train to the track while it travels through intricate loops and twists.