Which motor types? While using a motor as generator for example in wind turbines.
How less reliable? Let air out truck stops Put air back in truck brakes turn off. Besides the size of the drums and shoes are huge! Weight alone pushes tires into the ground and trucks stop a lot faster than you think. Given number of miles cars wreck a whole lot more than professional CDL drivers. Remember this when a CDL driver gets a ticket they cannot attend comedy defensive driving to get the ticket removed! Next time you see 72,000lbs stop in time. Thank the Westinghouse Airbrake Company from the 1930's And newer self energizing air brakes on trucks today