St Peter's central location means that it is easy to reach by train, bus or car.
The train station is 10 minutes walk from the College.
There are very frequent buses to London from Gloucester Green, just a few minutes walk from the College, and regular services to Heathrow and Gatwick airports.
Oxford can be very congested, but if you need to drive to the College there are public car parks nearby. At the start and end of the undergraduate term, short term parking is available in New Inn Hall Street by arrangement with the Porters Lodge. Follow the link for further information about driving and parking.