When I first got my R56, the nav system seemed to provide an estimated arrival time, I thought based on speed limits of the travelled roads. As I increased or decreased my speed the estimated arrival time would change.

Now it seems that the estimated arrival time is calculated not from the speed limit, but based on my rate of travel on the road.

In fact it's doing it so well that the estimated arrival on my last >70 mile trips has been within a minute or two of my actual arrival time.

Is my car getting smarter, or is this just an incredible coincidence?

HAL: I'm sorry Dave, I'm afraid I can't do that.

You do realize that it is constantly updating the ETA right? It gives you an intial ETA based on speed limits for the roads and then it keeps updating the ETA as you progress along your route.

Yes, I know this, and it used to do this frequently, but recently, especially if I am travelling on a long stretch of highway at a consistent rate of speed, it seems to make its calculation based on my rate of travel, not the speed limit of the road I'm on. For example if I go 65 miles on a road with a 65MPH speed limit, but I'm going 33MPH, It will tell me that I will arrive in 2 hours, not 1.

And I wish HAL would program itself to open the pod bay doors with one pull, but still lock them while travelling over 10MPH.

Jas.

Once you get going, it calculates it based on how fast or slow you are driving and how many miles it is, it has nothing to do with the speed limits of the roads

Well, that's not entirely true. The initial calculation is based on speed limits of the roads on the route, since it doesn't know how fast you'll be driving. It does seem to disregard the existance of traffic lights on any roads when making that calculation.