Tag:highway=motorway_link
+/- highway=motorway_link
The link roads (sliproads / ramps) leading to and from a motorway.
Used combinations in
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The link roads (sliproads / ramps) leading to and from a motorway. Normally with the same motorway restrictions.
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How to map
image 1
image 2
image 3
Mapping a motorway link is quite easy. In the first example (image 1) you can see a dual carriage motorway where another way (green) branches off. This green way should be tagged with highway=motorway_link and oneway=yes. Place the node where the green way branches off at the exit of the motorway as shown in image 2.
The second example (image 3) shows a more difficult junction. In this example you can leave the highway and enter it. For this create 2 different ways (orange) and tag them separately with highway=motorway_link and oneway=yes. Be sure to check the direction of the arrows. If there is no physical seperation (e.g. grass) in a part of the motorway_link you need the green way. In this example that green way can be tagged with highway=motorway_link and oneway=no.
Tagging
| Tag | Description | Example |
|---|---|---|
| ref=* | Reference number. | 16 |
| oneway=* | See section #How to map | yes |
| lanes=* | Number of lanes. | 1 |
| maxspeed=* | The maximum speed which is allowed (in km/h). | 100 |
| destination=* | Name of town for the direction of the motorway_link. Use the name of the city written on the sign which belongs to the motorway_link. | London |
Motorway junction
To attach more information for the motorway you should add the junction number.
- highway=motorway_junction Indicates a junction (motorway to other motorway) or exit (motorway to non-motorway). Tags ref=* and name=* should be set to the exit number or junction identifier. It belongs on the node shared by the junction of the motorway_link way and the motorway way.
Other situations
Parallel motorways
A parallel motorway should be tagged as motorway_link with the correct reference number (e.g. A 3)
Link roads between different highways types
If a road leads from a motorway to a non-motorway, only the portion that solely carries traffic to or from the motorway should be tagged as motorway_link. Any other roads used to connect the motorway to a non-motorway, which can also be used by non-motorway traffic, should be tagged as something less than motorway_link, usually the *_link of the non-motorway.
Motorway service areas
Besides its use for on/off ramps motorway_link can also be used for the slip roads into and out of motorway service/rest areas. In this case the motorway_link should go from the motorway towards the services as far as motorway regulations (for example no pedestrians) apply. This is usually indicated by a sign. Similarly the exit road from the services should be a motorway_link from the point where motorway regulations commence.
Examples
Huge Motorway junctions
This is a example of a more complicated junction between 2 different motorway junctions. You can see this in Germany quite often this example shows the Autobahnkreuz A 1/A 27 osm link.
If you take a closer look you can see the A 1 in blue lines going from left to right and the A 27 from north to south. The A 27 runs over the A 1 and therefore it is split into 3 sections. The dark blue part is a simple motorway with highway=motorway. The light blue part is tagged with highway=motorway,bridge=yes and layer=1.
In addition various junctions exist to get from one motorway to another. You can see that parallel to every motorway part runs a orange way. They are used as a link between the motorway and the original junction. They are tagged with highway=motorway_link and usually maxspeed=80 as you have to slow down there. The orange way beside the A 27 which goes from north to south is again split into 3 parts to insert the bridge=yes and layer=1 tags at the purple marked location.
The last parts of this junctions are simply the links shown in yellow and green which just the highway=motorway_link tag.
To enhance this junction some of the nodes could be tagged with highway=motorway_junction and the associated name. As well as a more complex way to deal with the layer=* and bridge=yes part to allow the renderer a better image processing.
Note for Germany: The links between the main motorways should only be tagged with the ref=* of the motorway they are going to, if there are signs or other sources saying, wich ref it is.
