Motorways in UK: M40 (London-Oxford-Birmingham)

M40 is a motorway connecting London to Birmingham, part of the European Route E 05, running from Greenock, Scotland, to Algeciras, Spain. 

M40 cover a distance of 89 miles (143 kilometers) and passes through four counties: Buckinghamshire, Oxfordshire, Northamptonshire and Warwickshire.

Motorways in UK: M4 (London-South Wales)

M4 is one of the major motorways in United Kingdom, London to Bristol and on to South Wales. 

This southern east-west motorway passes through fourteen counties: Greater London, Berkshire, Buckinghamshire, Wiltshire, Gloucestershire, Monmouthshire, Newport, Cardiff, Vale of Glamorgan, Rhondda Cynon Taff, Bridgend, Neath Port Talbot, Swansea and Carmarthenshire.