There have also been a few light rail attempts at it. The trouble is cost, plus you've got higher losses. Direct contact doesn't have much in the way of losses, but induction's tricky to do without it.
There are some (mostly automated) rail systems that use linear induction drive, though. The power pickup is via third rail like a normal train, but there's a large 'reaction rail' between the rails. The traction motor is a 'rolled out' stator from a 3 phase induction motor, and is mounted on the truck. No gearbox, the wheels aren't driven. I'm not sure why this was done, but I think it's to allow easier automation, since you can pretty much assure the brake rate all the time - no traction doesn't matter, you can brake on motor alone.
