External routing nodes are nodes than connect two roads on two map tiles together. They are blue in colour, diamond in shape and larger than other routing nodes. As in all routing nodes they must have the same coordinate but the extra precaution you must take with external routing nodes is that the coordinates must sit on the tile border.
Each map tile has a tile border which is green in colour. To make sure your external node lands on a tile border, look at where the external node is:
- If the external routing node is on the west tile border, it should have the same longitude of the tile’s west bound
- If the external routing node is on the east tile border, it should have the same longitude of the tile’s east bound
- If the external routing node is on the north tile border, it should have the same latitude of the tile’s north bound
- If the external routing node is on the south tile border, it should have the same latitude of the tile’s south bound
To find out the Map Bounds go to File Menu > Map Properties > Bounds tab.
An external routing node is marked in the Point Properties window under the Routing tab. Edit Point tool > right click on node > choose Point Properties > Routing Tab > Check Is external node.
External Routing Nodes exists in pairs – one on each tile, and the tiles must be adjacent to each other. If you have drawn an end node for a road which sits on the tile border but do not intend to draw its continuation on the adjacent tile just yet, do not mark the node as an External Routing Node. Leave it as an dead-end node, which is the blue small square, until you have drawn its partner on the adjacent tile.
Do not mark No U-turn for Turn Restrictions on an External Routing Node as this hangs the Garmin MPC compiler.
