The second example shows a more difficult junction. In this example you can leave the highway and enter it. For this create 2 different junctions (orange) and tag them separately with highway=motorway_link and oneway=yes. Be sure to check the direction of the arrows. The green way in this example can then be a simple junction withhighway=motorway_link without the oneway tag, as it is supposed to be used in both directions.

To attach more information for the motorway you should add further keys.

• maxspeed=Number indicates the maximum speed which is allowed.
• minspeed=Number indicates the minimum speed which need to be reached to use the motorway.
• name=Name of the motorway
• ref=reference name for example A 1, E 22
• highway=motorway_junction Indicates a junction (UK) or exit (US) ref should be set to the exit number or junction identifier. (use it on one of the nodes not the way)

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 splitted into 3 sections. The dark blue part is a simple motorway with highway=motorway and oneway=yes. The light blue part is tagged with highway=motorway,oneway=yes,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, oneway=yes 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 splitted 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 are also get just the highway=motorway_link and oneway=yes tags.

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 usually be tagged with the ref=* of the motorway they are going to--unless there are signs saying otherwise.