Currently all PRT "extensions" are left of the guide road.
I'd love to be able to decide where the guide road is in that order.
example:
road
guide road
road
road
expectation: one road should be placed to the left, two to the right of the guide road.
my suggestion is to let the line that is "same as selected +" represent the guide road.
instead of the + sign there should be two arrows ... one up and one down.
the up arrow places roads to the left of the guide road.
the down arrow places roads to the right of the guide road.
That is in relation to the drag direction.
the guide road should have a visual indicator so that a user knows if "up" is mapped to "left" or "right".
something like
"> Guide Road ^v"