Task: map a line of bollard nodes separating one-way directions of a road. You can certainly map them as a way w/o individual bollards as nodes. If you know the number, I think it’s worth it to map them individually; in my case, the line is straight and there are 12 bollards, with an equal distance between each pair. The challenge is to map them with the correct distance, and the solution is to use the terracer
plugin.
Install the plugin first. I’ll show the process for an imagined road:

It’s better to create a new layer (Cmd+n
) and work on it in order not to mess up the existing data, then merge the new objects back.
Map a line where the bollards are, in my case it’s a straight line:

Use the Extrude tool (x
) to create a small area out of the way — this is required by the plugin:

Use the More tools > “Terrace a building command” (Shift+t
). In the dialog, keep most of the fields empty (clear the Building field since we don’t need any tags) and enter the number of segments equal to the number of bollards minus one, # Segments = # bollards - 1
, in my case 11
:

Press OK. You’ll get 11 polygons, with the original line split into 12 segments of equal lengths:

Now you can use the Lasso selection mode (Shift+s
) to select the other set of nodes; if your line is pretty much vertical/horizontal, use the regular rectangular selection:

Delete them:

Then you need to add a tag to the nodes before removing the connecting segments (otherwise, removing the segments will also remove the “empty” nodes). A way to do that, if you’re on a fresh layer, is to Search (Cmd+f
) for new type:node
:

With the selected nodes, add a preset with F3
, search “bollard” and add “Highways/Barriers/Bollard”:

Now you can Search (Cmd+f
) for new type:way
and remove the selected segments:

Finally, Select All (Cmd+a
), click Edit > Merge Selection (Cmd+Shift+m
), select the original layer in the modal to merge the nodes there:

Done!