Looks like the curb begins at the corner of Castlebury and Chinden. Chinden does not have a curb.
I think this is a RTOL issue, since you're already in the Right Turn Only Lane at that point.
I don't know why the motorists can't use the middle lane, Chinden is a three lane road.
I have to assume that there is a soft shoulder to the right of the paved shoulder.
Also, the ticket was issued at 1700 hours (five PM) , so it was right at the beginning of rush hour, I wonder if that's got anything to do with it.