The single system you're describing, with all of its complexity, is a subset of what is required for autonomous vehicles. We will continue to have road construction, tunnels, and weather long past the last human driver. Improving the system here simply improves the system here -- you cannot forsake this work by saying "oh the autonomous system will solve it" -- this is part of the autonomous system.

But you can still impose a max speed limit based on available data to cover most normal driving conditions but it's still on the driver to drive slower if appropriate. And that could be implemented today, not a decade from now when autonomous driving is trustable.

The parent post said that autopilot won't let him go over the speed limit and implies that makes him safer. My point is that you don't need full autopilot for that.

So this is not a technical problem at all, but a political one. As the past year has shown, people won't put up with any convenience or restriction, even if it could save lives (not even if it could save thousands of lives)

GPS is extremely accurate honestly. My garmen adjusts itself the very instant I cross over a speed limit sign to a new speed, somehow. Maybe they have good metadata, but its all public anyway under some department of transportation domain and probably not hard to mine with the price of compute these days. Even just setting a top speed in residential areas of like 35mph would be good and save a lot of lives that are lost when pedestrians meet cars traveling at 50mph. A freeway presents a good opportunity to add sensors to the limited on and off ramps for the car to detect that its on a freeway. Many freeways already have some sort of sensor based system for charging fees.

What would be even easier than all of that, though, is just installing speeding cameras and mailing tickets.

Just add all those to the map system. It could be made incredibly accurate, if construction companies are able to actually submit their work zones and "geofence" them off on the map.