Pinewood Studios, where Space: 1999 was filmed from 1973-1976, is 20 miles (30km) from the centre of London. In the 1970s few people had cars, and the 1973 oil crisis made petrol expensive and sometimes unavailable, to the point that petrol rationing was considered. Most ordinary members of the cast and crew relied on public transport, but Pinewood was not easy to get to.
The nearest public transport is 4 miles away in Uxbridge, which has a train station and the end of the London Underground Metropolitan line and the Piccadilly line. A public bus goes to the nearby town of Iver Heath, but there is still a 30 minute walk to the studio gates. The studio provided a private coach service between Uxbridge and Pinewood. This is the schedule from April 1976 (from Raul Newney, who played Dr Nunez in Mark of Archanon, thanks to Simon).