Well, quite. But again this is all supplementary information. The car should have a basic idea of the speed limit from a database and it should adjust as approp

Well, quite. But again this is all supplementary information. The car should have a basic idea of the speed limit from a database and it should adjust as appropriate. Similarly the car should be able to identify road surface conditions and also how much power it's needing to put in to achieve a set speed. If it's identified that traction is being lost over gravel, then it should reduce power. Equally the autopilot should consider visibility. There are plenty of roads that are national speed limit and you'd be insane to drive at 60 on them due to blind or extremely tight corners. But with LEDs this seems like massively over-engineering the problem. Why use computer vision when you can potentially broker a deal with the highways agency to get live speed limits on a particular stretch of highway?