I always think the main issue is the getting onto the cycle path in the first place.
I either have to stop to turn right, slowing traffic and sitting in the middle of the road.
Or do dodgy roundabout/pedestrian crossing maneuvers which runs the risk of cycling into lampposts (also conveniently located in the middle of the cycle path entrance coming out the south of Abingdon).
Its easier coming off site, but there is still the issue of re joining the traffic again.
But then the same right turn issue with the road between Drayton and Abingdon.
Maybe its just me being too clumsy to do right angles at speed.
There is a very nice slip road onto a cycle path somewhere in oxford they should have more of those.