On what basis does Nuvi recalculate routes?

[TWHH]

Hi all,

When driving a considerable journey, say from London to North Wales, the little triangle often appears which when pressed says that there is a better route available.

I was just wondering on what basis the Nuvi decides that a better option exists. Is this because of traffic probelms ahead which weren't there when the route was first calculated? Is it because it's just had a rethink as it's got nearer to a turning/junction?

As most people say, it kinda makes sense to sense check a GPS's route with a good old fashioned map, or include any local knowledge you might have about as specific road before living your life by the SatNav, but when you're doing 70 (and not 1 mph more) on a motorway you can't do this, especially if the Nuvi comes up with a 'more suitable' route 4 times an hour.

Would be good to know what thought processes my tusted travel companion is going through.

Thanks

[swing]

The Nuvi records your average speed on a variety of different road types. As a result of your driving style / the general flow of different roads, it will occasionally work out that a change of route will shortern the ETA, and offers this route.

Other reasons for offering a different route are:

a. There is traffic on your current route (from TMC receiver) which results in another route being better (although this is normally handled through an empty triangle for you to manually deal with).

b. The traffic receiver has been told the traffic (which caused you to reroute) has cleared and hence there is a faster route (likely to be using some of the original route).

c. The traffic receiver has simply lost it's traffic signal and hence thinks the traffic has cleared, and hence offers some of the original route (which may make the journey longer).

Very occasionally, it will simply be that having spent more time thinking about the routing, it has found a better route.

[TWHH]

Thanks for the reply. This kinda concurs with what I thought would be the case, it's just that the other day it seemed to come up with a 'better' route every 5 minutes.

We see you’re using an ad-blocker. We’re fine with that and won’t stop you visiting the site.
Have you considered making a donation towards website running costs?.
Or you could disable your ad-blocker for this site. We think you’ll find our adverts are not overbearing!