Generally if coming directly from the North or South it is probably easier to take the A34 from either the M40 (North), or M4 (South). Exit the A34 at Abingdon South (A415) and head into Abingdon centre, leave north on the A4183 (Oxford Road), Northcourt Road is 1 mile on the left.
Oxford Train Station and then X3 bus as below
Oxford Bus X3 from Oxford (Train Station) to Abingdon (Oxford Road at Northcourt Road, Boundary House); three times per hour, takes 28mins. Ground is on Northcourt Road adjacent to this junction which is 3mins walking distance of the ground.