19th century

Much of the present day A565 route from Liverpool to Thornton is unchanged since the Victorian age.^[3]

20th century

A bypass of Formby, now forming part of the A565 was constructed during 1936–1937 at a cost of £195,463 (equivalent to £13,418,186 in 2021). It was opened on 10 December 1938 by Lord Derby, with the ceremony taking place at the Southport end of the road. At a width of 120 feet (37 m) and length of 4 miles (6.4 km), it shortened the route by nearly 0.75 miles (1.21 km).^[4] The Ministry of Transport provided a grant of 60% towards the construction cost.^[5]

The A565 route was included in the Trunk Roads Act 1946, designated in its route from Bootle through to Tarleton.^[6]

21st century

A bypass of Thornton, Merseyside, known as the A5758 Broom's Cross Road, was constructed during 2014–2015, linking the A565 at Thornton with Switch Island junction, having been planned since the 1960s.^[7]

Liverpool City Council announced in 2016 that they had appointed a construction company to create a new dual-carriageway road in Liverpool, involving the widening of Great Howard Street and Derby Road, a 1.7 miles (2.7 km) stretch, at an expected cost of £18million,^[8] which had risen to £22million by the time the work started in May 2017.^[9] The council deemed the works necessary given the road would be a vital route for freight traffic to and from the Liverpool2 deep water container terminal, in addition to an associated tunnel and bridge which required replacement, having failed a structural assessment.^[10]