Drive Tires vs. Break Tires

Friction is an enemy to MPG.  Friction is a friend to stopping.  Tires on the road are the friction that makes a car go and stop.  So how can you make tires that give you awesome efficiency while driving and stop you quickly when you need it?  Two sets of tires on the same car.  It would require a lot of engineering but the way I imagine it there would be a skinny motion wheel that would be on the ground at all times.  Skinny means less friction and greater MPG.  Then right next to it you would have the break wheel that would engage when the breaks or steering needed the added friction.