The top left photograph of Birmingham International Airport is a typical characteristic of the rural-urban fringe. The building of new runways due to increased economic pressure always creates controversy. Top right shows the south Birmingham transport hub, where the air, rail and motorway networks converge. Left - shows office of British Gas based at the Blythe Valley Business Park, with good transport links to Junction 4 of the M42 and the A34 Stratford Road into Birmingham. Greenbelt land around cities was designated in the Town and Country Planning Act to restrict development (of buildings) and to preserve and conserve the countryside for farming and recreational purposes around Britain's cities.