[1] The main reason for the motorway was to provide a through route to the new Mersey Road Tunnel, Kingsway, which was built at the same time.

[4] The M531 would have run from a point just west of the current junction 5 and provided a connection with the M56 for eastbound travel.

When the M53 was first planned in the early 1960s, it was designed as a route to connect the two Mersey road tunnels with the A55 trunk road on the Welsh border, giving Liverpool and the rest of Merseyside a direct link with Chester and the towns on the North Wales coast.

The route to North Wales was unresolved as there was even an option to run due west from south of junction 4 and cross the River Dee on a barrage.

This first section from the tunnel to junction 5, where it connected straight into the Vauxhall Motors road, was opened by Lord Leverhulme in a ceremony at Hooton on 1 February 1972.

[9] Manchester M56 Data from driver location signs is used to provide distance and carriageway identifier information.

[11][12] A full-sized replica of one of the motorway's bridges forms part of the exhibition O' Magic Power of Bleakness by Mark Leckey at Tate Britain (September 2019 – January 2020).