The "Preston By-Pass" was Britain's first motorway, opened in 1958 by the Prime Minister, Harold Macmillan. The road that appeared then was barely a motorway by today's standards - two lanes each way with soft shoulders, a broad central reserve with a hedge, and just one junction in the middle. It ended at a roundabout on the A6 to the north and south of Preston.
These booklets were published to accompany the inauguration of work, and then the official opening of the motorway, and show a road that bears almost no resemblance to the M6 of today.
Further reading on the M6 Preston Bypass.