- Section – on the American Discovery Trail a Section is a continuous section of the trail within a state, some states have more than one section, Colorado and Ohio have three each, the northern route, the southern route and the shared part of the route in each state. There are currently 20 Sections on the American Discovery Trail.
- Segment – Each Section consists of multiple Segments, a Segment usually travels between significant locations, cities, or geographically significant points, etc. Some Segments are ‘alternate’ segments which provide a route avoiding an obstacle to a type of travel. Bicycle routes for instance avoid places where bicycles are not allowed or where it would be impractical to ride. The new database will add more kinds of alternates, for example ‘scenic’, ‘historic’, and eventually Segments submitted by users, things like ‘Favorite hikes off the American Discovery Trail’. There are currently 154 segments on the American Discovery Trail.
- Waypoint – each Segment consists of multiple Waypoints, a waypoint is a significant point on the trail, though the significance can vary greatly from the St Louis Arch to a cairn on a mountain! (The latter may be more important when you are trying to find your way over a mountain in the clouds…) Waypoints are intended to help navigate and also provide information about their location, they are represented in the GPX as real GPS waypoints, each waypoint is also listed in the Turn By Turn documents (TBT). There are currently 4,200 waypoints on the American Discovery Trail.
WAYPOINTS ARE THE MOST IMPORTANT data item about the ADT route and should be used as the basis for any communication about the route. A waypoint is identified by its ‘label’ which looks like this ‘A10010’ (which is Cape Henlopen), or for waypoints in alternate segments, ‘JZ0090’.
- Tracks – tracks are strictly a GPX item, there is one track for each segment.
- Trackpoints – each track consists of many Trackpoints, trackpoints are simply points that get joined together to make up a line representing the trail on a map. They are created either by recording with a GPS unit or by drawing with GPS mapping software. They are similar to waypoints but only have location and elevation information. There are currently 122,000 trackpoints on the American Discovery Trail.
- Routes – a route in GPX terms is a suggested route between two or more points. There are currently no Routes in the American Discovery Trail GPX files. As an example if you get driving directions from Google Maps it provides a Route. You may then get information as you drive like “found a faster route”, which if you accept it will change the route, many GPS systems can do this. However, since we don’t want the American Discovery Trail route to be changed on the fly, we will probably not use routes. (If we could teach a GPS system to understand the concept of American Discovery Trail routing it might be a very useful feature for getting around temporary trail closures like floods, closed bridges etc., but until then…)