Because following a GPS blindly is stupidity...yes in this case it has been out 10 years.. but what if it was out 10minutes or what if it was some other hazard in the road or some road workers fixing somthing... you should be paying attention to the road and signs....now I agree signs should have been there. But just because the satnav says okay doesn't mean driver can just blindly follow, you are a dangerous driver not aware of your surroundings and in wet conditions going too fast for the distance you can safely see.