Get rid of map control completely (and especially those super-imposed command zones), and replace it with a steady trickle of (optionable) slow/medium/fast reinforcement points.
Command Vehicles are still used - to call for reinforcements (those reinforcements enter the map at the nearest location to the CV (if that's programmable). It's entirely up to the player to locate where that will be, and "secure the area".
The game doesn't automatically end if a player loses all CV's, but they can't call for reinforcements until they buy a new CV (maybe there should be some kind of delay in its arrival, to mimic the breakdown in command structure).
Call it "Hardcore Mode" and sit back as players finally
have reason to explore the Hell's Highway map in its entirity (and others).