If you go to the heaviest of land based transport systems (freight railroads), you will find "Dynamic Brakes"; which use the traction motors as generators dumping electrical power into resistor grids (toaster wires), generating MegaWatts of heat and drag. Why do railroads use this technology - overall it is cheaper than totally relying on friction brakes.
There are other ways to electro-magnetically create drag than motors/generators. Take a look at the North American Eagle land speed record car - its high speed brakes work just like the magnetic damper on a postal scale - drag is proportional to velocity.