any idea what's deal with green poles along the A1 from Geneva to Lausanne?
Don't know about these particular ones, but often poles are used to indicate where snow plows can shoot snow off to the sides, and where they should not. For example, before a bridge, they will put red poles, then green poles after the bridge. They are only put up during winter months.
Maybe the poles you're talking about are completely different, I have no idea based on the description.
These form part of the new Swiss infrastructure under construction for better traffic signage. Many will have horizontal bars connecting the two poles to display signs. These are meant to be green in rural areas and grey in urban areas (you see the grey ones already on the A1 in/near the Lausanne area).
RTS has a description of these green poles on their Instagram account here :
An anecdote- one council worker was driving the tractor and the other standing in the big metal 'bucket'at the front, and planting poles as they went along. At lunchtime they drove past to come home to eat at great speed, one worker still in bucket, holding on for dear life. Switzerland, hey!