Question

Buses and trucks have wider wheels some of them also have double wheels at back . why?

Answer 1

to transfer the pressure over large area ...other wise concentrated at one point can be distributed by two points. so the load is dispersed in wider area.

Answer 2

Answer:

To prevent excessive Pressure.

Explanation:

If the wheels are wider, then area increases. And if area increases, pressure decreases.  So, the buses and trucks would not have to face so much pressure and can have the ride smoothly without any breakdowns or Tyre puncture.