a self-driving car should be a human replacement

I think this is something to strive for too, but our AI just isn't there yet. Yes, this is essentially a method of compensation... for now.

So let's say that we do eventually develop a human-like perception and AI (or better) for this application. What incentive would you have to remove the CAD library functionality? You can argue that it's a crutch right now, but in the future it will be touted as a feature. Indeed, instead of having teams of people with surveying equipment romping around, the sensory data from the cars is inputted into the CAD database.

Example: A car changes lanes because 700 ft. ahead (too far for sensor perception) the database knows there's some potholes in the previous lane, as perceived by the car that traveled through the area earlier, right after a heavy downpour.

A normal driver should be able to find its way reading signs and having a general idea of the route to take. I don't see why a self-driving car shouldn't do the same. If self-driving cars can operate without needing preloaded data, you don't need all that disk space at all: just lots of realtime calculations

You're trying to implement human perception and processing in a computer (a good idea), but strip it of all of the benefits computers have over us. The two can work together for a system far superior to human-like perception and processing alone. We don't have a perfect track record, after all. And the cost of disk space? Well, we all know what direction that's headed.

And... we kinda do depend on a database to find our way, it's just not 3D CAD. And of course, Google already owns the most extensive database (Google Maps).

Whatever it takes to make auto-automobiles (heh) a reality as soon as possible... well, I'm for it, as long as you can maintain a failure rate lower than human error. I can understand your disappointment in the impurity/immaturity of the tech though.

Appreciating the discussion. :)