@Voland, Re: Slip road limits
So you have two things. The accuracy of the GPS unit an then the accuracy of the map itself. The map is accurate to 1.5 meters. Then your GPS can be off, depending on the number of satellite signals it receives and of course your GPS unit will snap you to the road link based on direction of travel and speed. When you're in a tunnel, the GPS unit uses its sensors to determine your relative position from when you last received a sat signal.
So that's the issue with your position on the map. And again each road link has a set speed attribute for your vehicle type. (car or truck)
The ability to read signs would be to augment the system and if you start to get to autonomous driving, your GPS enabled car will have road cameras among other technologies...
Biting the hand that feeds IT
