Originally Posted by
Kevin AA
In some cities (Paris and Montreal come to miind), the trains use rubber tires instead of steel wheels. This is much quieter at low speeds but not so much at high speeds.
Rubber tyred metros provide a really crappy ride quality. They can't reliably do anything over 30 mph. The noise that you hear on all the VAL systems and these rubber-tyred metros is due to motors not designed to operate above 35 mph, and the noise of tires on the track. VAL systems are great in that they don't require as much track maintenance as wheel-on-rail systems, but generally require a larger loading gauge for similar capacity and have their own problems.