[citation needed] Built in 1959 when the M1 (as part of a link from London to Birmingham) went as far as Junction 18, the M45 was designed to dissipate some of the motorway traffic before the M1 terminated.

As the signposted route to Birmingham, accompanied by a boom in private motor ownership in the 1960s, the M45 (and its effective continuation, the final 30 miles (48 km) or so along the predominantly dual carriageway A45), formed a key leg of one of the busiest roads in Britain.

[2] In 1972, the opening of the M6 parallel to the north provided a much faster route through to the West Midlands from London.

A limited-access junction (Eastbound exit and Westbound entry) was added in September 1991,[citation needed] around two-thirds of the way along from the M1, south of Dunchurch, the main southern suburban village (to Rugby) nearby.

The choice of routes means that logistics operations are an important part of the economy of Coventry and Rugby.