The only option left I think is to come beyond St James roundabout and then a long sharp turn back.
If the old Arkelston to Renfrew line hadnt been upgraded cycle path wise then potentially this could have been used then diverted to airport then on to Linwood and Bridge of Weir and Kilnacolm, but that is gone now
If the old Arkelston to Renfrew line hadnt been upgraded cycle path wise then potentially this could have been used then diverted to airport then on to Linwood and Bridge of Weir and Kilnacolm, but that is gone now