- Section – on the ADT a Section is a continuous section of the ADT 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 ADT.
- 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 some 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 ADT’. There are currently 154 segments on the ADT.
- Waypoint – each segment consists of multiple Waypoints, a waypoint is a significant point on the ADT, 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 ADT.
- 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 ADT 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 ADT.
- Routes – a route in GPX terms is a suggested route between two or more points. There are currently no Routes in the ADT 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 ADT 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 the ADT routing might be a very useful feature for getting around temporary trail closures like floods, closed bridges etc., but until then…)