And park closer together. I imagine my office parking lot's physical capacity would increase by at least 60% if we didn't have to get in and out of the vehicles. It already has capacity for around 1000 workers (maybe more).

Even if they didn't move the lot, my car could drop me off at the entrance and then go find an available spot. The lot is huge, close to a 1/4 mile walk from the furthest available space to my entrance. I wouldn't mind not having to worry about that on those days I'm running late.

And they won't need as much space for backing/driving- especially if they can communicate with each other- a car that is blocked in could signal the other cars that it needs out, and they could move to make space for it to get out.