There are frequent coach services to Heathrow and Gatwick (The Air Line). The journey from Heathrow takes just over an hour on a good day (a little longer from Terminal 4) and two hours from Gatwick. Tickets can also be bought on-line. There is a free shuttle service between Terminal 4 and the other terminals. A taxi from Heathrow to Oxford will cost you at least £50. Most taxis take four passengers. This is a rather expensive way of arriving at Oxford. There is a less frequent service to Stansted Airport (757 via Stansted). From Luton airport, a coach runs every 2 hours. The journey time is around 2 hours. More frequent connections are available by train. Trains run from Luton Airport Parkway station to Oxford via London. Two changes are necessary, the train arrives at St Pancras then you must take an underground link to Paddington, from which trains run to Oxford, see
http://www.nationalrail.co.uk/. The journey time is about 3 hrs. . Birmingham International Airport (BHX) is a good alternative airport for travelling to Oxford. The train station is linked to the passenger terminals by a free, frequent Air-Rail link, which runs every 2 minutes from 0515 to 0200. The journey time is less than 2 minutes. There is a frequent train service from Birmingham International train station to Oxford, and the journey time is approximately one hour. Timetables can be found at
www.nationalrail.co.uk.