Hi, I've done a small test with two tiles and a couple of boundary nodes (NOD 3). This by manual editing of .mp-files, so there may well have been errors on that side. Results: * Only one of the two tiles displays. * Routing across tile boundaries works to some extent. It routes through the undisplayed tile, so the NET/NOD stuff is probably ok. It seems like maybe a boundary node had better not be a junction: Routing seems to work better across those boundary nodes that were inserted into the middle of a road, and some routes that were suboptimal could be explained by not taking a junction boundary node. Anyway, it looks like NOD 3 is all that's needed for routing from tile to tile -- no extra index in the gmapsupp.img or anything required. Regarding the display problem: I cut the map up from a very small neighbourhood map which has some problems itself. In particular, it doesn't show street name popups. Larger maps seem to behave better, so my hope is that the display problem would go away on larger tiles. Steve, do you intend for mkgmap to handle the cutting up eventually? Otherwise, my suggestion would be to leave this to external programs and have these put a tag (say mkgmap:boundary=yes) on the boundary nodes. Cheers Robert