eli5 Why do trains with steel wheels have traction on steel rails, but if your brakes on your car are used up and become steel on steel they dont work anymore?

Question

eli5 Why do trains with steel wheels have traction on steel rails, but if your brakes on your car are used up and become steel on steel they dont work anymore?

In: 1231

Answer 1

Worn brakes on your car do work, they just work very poorly when the pads are worn down to steel.

There is still friction with a steel to steel contact, but much less than with brake pad to steel.