Objects #

OSM is made up of objects, also known as elements. Objects are the basic building blocks for everything, including roads, houses, lakes, parks, and bike routes.

Here are basic descriptions of objects:

1. Node: coordinates with an assigned ID.
2. Way: a series of connected nodes.
3. Area: a series of ways that start and end at the same node.
4. Relation: objects that are grouped together by a similarity.

Each object is further defined by tags. Tags are key-value pairs written as KEY=VALUE.

For example, a way with the tag highway=cycleway denotes a way that is intended for bicycles. An object may have many tags to further define its purpose.

Nodes #

Nodes are latitude and longitude coordinates with a unique ID. As standalone objects, they may indicate features such as benches, ATMs, or bus stops.

---
title: Nodes
---
flowchart
    Node1((Node 1))
    Node2((Node 2))
    Node3((Node 3))
    Node4((Node 4))

For mountain biking, a standalone node often describes a trailhead. For example, a trailhead may be a node with the following tags:

Ways #

Ways are a series of connected nodes. A way is either open or closed. An open way starts and ends with a different node, forming a line. A closed way starts and ends with the same node, forming a loop.

---
title: Open ways
---
flowchart LR
    Node1((Node 1)) -->
    Node2((Node 2)) -->
    Node3((Node 3)) -->
    Node4((Node 4))

For mountain biking, ways often describe trails. For example, a mountain biking trail may be a way with the following tags:

Traces #

Traces are a series of GPS coordinates. They are created by a GPS device, such as a smartphone.

Although traces are similar to ways, you cannot use traces as map objects without converting them to ways. To do this, import a trace to OpenStreetMap, edit it, and save it as a way.

For more information, see Traces.

Areas #

An area is a closed way with the tag area=yes. Areas may also be created from closed ways with other tags, such as landuse=forest.

---
title: Areas
---
flowchart LR
    Node1((Node 1)) -->
    Node2((Node 2)) -->
    Node3((Node 3)) -->
    Node4((Node 4)) --> Node1((Node 1))

For mountain biking, areas may described designated biking zones. For example, a park specific to biking may be an area with the following tags:

Relations #

A relation is a collection of related objects. Relations associate objects when tags are not sufficient.

---
title: Relations
---
flowchart
    subgraph Tinton Trail #55
        Node1((Node 1)) -->
        Node2((Node 2)) -->
        Node3((Node 3)) -->
        Node4((Node 4)) --> Node1((Node 1))
    end

For mountain biking, relations may associate multiple trails with the same trail system. For example, a trail system may be a relation with the following tags:

Each way, node, or area associated with the trail system is part of the relation.

Previous Next