[tomatotomato37]

Most ICE vehicles with automatic transmissions (aka 90% of them) either explicitly open the clutch or do torque converter things when off throttle, the result being that the vehicle starts freewheeling. Air resistance and friction and what not means the vehicle will eventually stop, but in a modern car at highway speeds that stopping distance can still be multiple miles; and that's before you bring hills into the equation.

My point being for most people expected behavior is for a car to only slow down during active braking and maintain momentum otherwise, and trying to change that otherwise would bring more danger than it's worth.