The A14 is a trunk road in England, running 127 miles (204 km) from the Port of Felixstowe, Suffolk to its western end at the Catthorpe Interchange; a major intersection at the southern end of the M6 and junction 19 of the M1 in Leicestershire. The road forms part of the unsigned Euroroutes E24 and E30.
From the Port of Felixstowe the road heads west, bypassing Ipswich to the south via the Orwell Bridge and to Stowmarket, Bury St Edmunds, Newmarket and Cambridge where it meets the M11, then past St Ives, Huntingdon and the junction with the A1, from there through Kettering, Northamptonshire, ending at junction 19 of the M1 and the start of the M6.
The road is a dual carriageway, most with two lanes each way, but there are two dual three-lane sections: on the Newmarket bypass (between Junctions 36 and 38) where it runs concurrent with the A11, and a short stretch between the Girton Interchange and Bar Hill. There are three at-grade junctions: with the B663 at Bythorn in Cambridgeshire (junction 15); at the Leighton Bromswold turn a few miles to the east (junction 17); and at the Dockspur Roundabout at the edge of Felixstowe (junction 60), although at the A14/A1 junction (junction 21) and at the A14/A141 junction (junction 23), the road's main route does have to negotiate a roundabout (in the case of the latter, the A14 southbound and a spur goes underneath the roundabout, as the A1 does at the former).
The current A14 includes parts of the former A45 between Felixstowe and Cambridge, the A604 between Cambridge and Kettering, a short stretch of the former A6 west of Kettering, plus a new link road which was constructed in the early 1990s between there and the M1/M6 interchange at Catthorpe, Leicestershire. Prior to the current A14, the main route from Birmingham to the Haven ports followed the M6, M1, the A428 and A45 road via Coventry, Rugby, Northampton, Bedford, St Neots, Cambridge and then through all the towns on the A14 to Felixstowe. Prior to its use for the current route the A14 designation had been used for a section of road between the A10 at Royston and the A1 at Alconbury following part of the route of Ermine Street which now, in most parts, is designated the A1198.
The M45 motorway was constructed in 1959 parallel to part of the old A45 in the Midlands. It opened on the same day as the M1 motorway and was soon one of the busiest sections of motorway. The M6 opened in the late 1960s and early 1970s, after which more traffic to the ports used the route from junction 1 of the M6 via the A427 to Market Harborough followed by a short section of the A6 to Kettering and then the A604 to Cambridge before joining the old A45 to the ports as above. The M45 now carries little traffic.
The sections from Huntingdon east to the ports were upgraded first, starting with the Huntingdon bypass in 1973, followed by the Girton to Bar Hill section in 1975/76 and the Cambridge northern bypass and Cambridge/Newmarket section in 1976/77. The Bar Hill to Huntington section opened in 1979 prior to the M11 which was fully opened in 1980. The Ipswich southern bypass including the Orwell Bridge opened in 1982.