[mkgmap-dev] problems at map intersections?

Sat Jul 18 10:20:04 BST 2009

> Yes, I noticed that - but could not reproduce it yesterday. Please
> notice however, that the route you found has both starting points at the
> lower map. That may or may not have anything to do with it. Your picture
> also shows that the upper map vanishes (which you confirmed already).

Well, it will route through the tunnel with the starting point on the
lower tile and the destination point on the upper tile. Just done that.

> > Now, this may be because mapsource thinks that using the tunnel and
> > then looping back to the S again is not a good route so it decides
> > you're better off going to the E. If that's the case, I don't think
> > there is anything we can do about it.
> 
> If you could recheck with a map without the split, you'll see that
> routing through the tunnel is no problem at all. Just download some
> surroundings of the tunnel and build a map to try it.

Well, I believe you so I won't bother to do that.

It is not inconceivable that there is something in the Garmin code
code that modifies the routing behaviour when the route crosses a tile
boundary. Perhaps, it limits the number of times it crosses the
boundary? Anyway, as it can actually route through the tunnel but
prefers not to, I can't, at this time, see how we can do any better.
Sorry.

Cheers,

Mark