Why do some subway systems (e. g. Paris, Montreal, Mexico City) have rubber tires instead of steel wheels?

Question

Why do some subway systems (e. g. Paris, Montreal, Mexico City) have rubber tires instead of steel wheels?

In: 313

Answer 1

Its cheap.

You just need a flat surface where tires can run on. The suspension is far simpler with rubber tires and also you can use existing truck workshopw to do maintenance on the tires.

Also some standards might not apply because of vehicle size, weight or technology. Which again saves cost.

It doesn’t really necessary provide a smoother ride as the vehicle is a bit less stable at higher speeds and the savings on the suspension show.

So overall.. simplicity, cost, weight savings etc.