Please note these are directions from the main Oxford train station, not Oxford Parkway.
Exit the train station by walking downhill past rows of bike racks. At the end of the bike racks, take the pedestrian crossing across the road. On the opposite side of the road is the Saïd Business School, follow this with the building on your left side. Continue up this road (Hythe Bridge Street) until you get to a large junction with traffic lights. Follow the pavement round to the left until you reach another set of traffic lights. Take the pedestrian crossing across the road to Beaumont Street. Walk up Beaumont Street until you see a large neoclassical building on the left, this is the Ashmolean.