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.