| +/- highway=motorway_link
The link roads (sliproads / ramps) leading to and from a motorway.
How to map
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.
|ref=*||Reference number, if one exists (i.e. a route takes an exit from a motorway).||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|
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.
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.