Why is it so difficult to drive backward in a straight line?
In: Engineering
It takes practice. I drive company vans and box trucks for work and used to suck at it now I can back up to a dock no issue with just my mirrors.
The other two main answers are about the mechanics of the car. The caster angle of the front wheels and the pivot point of the car in reverse.
I’m going to counter both of those and attribute it to operator error.
[removed]
If you drive forward the wheels and therefore the steering wheel will centre if you reverse due to the steering geometry they don’t and therefore you have to correct the straight line manually
Take a pencil and move it along a table in a straight line.
If you pull the pencil from its tip it’s easy.
If you push from the eraser end it’s very difficult to keep it straight.
Same principle.
[removed]
Its really not dificult at all. Engage reverse gear, foot off brake and onto gas, don’t turn the steering wheel, back up in a straight line.
In what world is that difficult?
ELI5. When steering is at the front, the rear wheels follow. Any small deviation will result in the rear wheels adjusting slightly to follow. This is a stable configuration. Small deviations self correct. For eg, if you are constantly off by half a degree, the car continues in roughly the same direction, just slightly curved. Wheels all point the same direction.
When the steering is at the rear, to keep the car in a straight line, the rear wheels need to constantly adjust to follow the line of the front wheels. Small deviations do not self correct. This is unstable. So if you are constantly off by half a degree, the direction the front wheels and rear wheels face will get further apart. Wheels pointing in different directions just gets worse. Car eventually spins.
I saw another answer mention forklifts, which I think is a pretty good example. Next time you’re at a supermarket and see a manual pallet jack with no load, ask the clerk politely if you can try pushing it forward, straight. You’ll see it’s surprisingly difficult as the steering axle is at the back – just like driving in reverse.
Imagine if you drive forward but your back wheels turned, it might make more sense like that
Latest Answers