To do this, just make two parallel roads next to each other, both one-way. In Potlatch 2, there's an option to make a parallel way next to the currently selected way. To do this, just click "Make parallel" on the toolbar in the bottom right corner of the screen and then move the mouse to the area where you want the way to be. Then copy over the tags from the other way (hit the "r" key) and make sure both ways are marked as one way in the correct direction.
If it's a grass median such as US interstates, then create an area between the two carriageways and tag it landuse:grass. Long lengths of road medians can be worked on in sections then joined together later.
Discussion
Reäksje fan compdude op 6 maaie 2011 om 16.09 oere
To do this, just make two parallel roads next to each other, both one-way. In Potlatch 2, there's an option to make a parallel way next to the currently selected way. To do this, just click "Make parallel" on the toolbar in the bottom right corner of the screen and then move the mouse to the area where you want the way to be. Then copy over the tags from the other way (hit the "r" key) and make sure both ways are marked as one way in the correct direction.
Hope this helps.
--Compdude
Reäksje fan Former OSM contributor op 7 maaie 2011 om 13.22 oere
If it's a grass median such as US interstates, then create an area between the two carriageways and tag it landuse:grass. Long lengths of road medians can be worked on in sections then joined together later.