Placeholder Image

Subtitles section Play video

  • When you turn a car’s steering wheel, the car follows a path along the same curve regardless

  • whether you go forwards or backwards. So it seems like it should be just as easy to steer

  • going backwards as going forwards. But clearly, it's not.

  • Suprisingly, the difficulty of driving backwards has almost nothing to do with the direction

  • youre facing and everything to do with the fact that you steer using the front wheels.

  • When driving forwards, a car goes in the direction the front wheels are pointed. And when driving

  • backwards, the car goes where the back wheels are pointed. Simple! But the difference is

  • that going forwards, the direction of travel is determined by the same wheels you steer

  • with, so you just point them where you want to go, and that’s where you go, the back

  • wheels follow automatically. In physics, we call this a “stablesystem, like dangling

  • a pencil from your fingersmove your hand around and the pencil follows, no thought

  • required.

  • However, when driving backwards, the direction of travel is determined by the back wheels

  • but you steer with the front wheels. So rather than just pointing the front wheels where

  • you want to go, you have to point them in the direction that will get the BACK wheels

  • to point in the direction you want to goit’s an additional level of separation before the

  • car does what you want. And in fact, if you don’t make any corrections, then over time

  • the back wheels point farther and farther away from the direction you want to go: instead

  • of following the front wheels, they want to run away!

  • This is an unstable system, like trying to balance a pencil on your fingertip. It’s

  • incredibly finicky and requires a ton of coordinated hand-eye feedback to maintain. That’s why

  • you constantly have to readjust your steering when driving backwardsmathematically,

  • your car is like an upside-down pencil!

  • Of course, there are some successful rear-steering wheeled vehiclesforklifts, for example,

  • drive only slowly and choose rear-steering for greater control of their forks.

  • But let’s go in the other direction and add a TRAILER to your carsteering backwards

  • has gained ANOTHER level of difficulty: you use your front wheels to get the back wheels

  • to point in the direction needed to get the TRAILER to point in the direction you want

  • to go. Not complicated enough? It becomes worse the more trailers you addeach one

  • adds another level of separation between the direction of your steering and the actual

  • direction of travel. Which is why it’s nearly impossible to push on one end of a chain or

  • a rope and have the other end go where you want it to, and why you will never, ever balance

  • a flexible rope or chain upright on your finger. Makes backwards driving seem downright easy!

When you turn a car’s steering wheel, the car follows a path along the same curve regardless

Subtitles and vocabulary

Click the word to look it up Click the word to find further inforamtion about it

B1 US direction steering driving steer pencil front

Why is it Harder to Drive Backwards?

  • 608 32
    Ashley Chen posted on 2015/03/02
Video vocabulary