What are "NMPs"?
I addition to what Jim wrote, it's also important in the Highway Browser.
For instance, click on the first waypoint of
GA2. You can see the '
Intersecting/Concurrent Routes' in the info window. When you click on the link (GA193), the route is opened. It makes it easy to navigate through the routes.
Intersection/concurrent routes are detected by their waypoint coordinates. They must match. If a waypoint has slightly different coordinates, we call it 'near-miss point' (NMP).