Highways Agency Project Manager, Mark Saunders, said:
We have worked hard over the past week to get the additional lanes open to traffic in both directions.
The A14 westbound between Histon and Girton opened to traffic at about 7am this morning with a 50mph speed limit in place due to safety reasons.
The additional lane on the eastbound carriageway was opened on 2 April.
To help people making journeys over the Easter bank holiday, work was suspended from Thursday 2 April and resumed on Tuesday 7 April.
Opening the extra lanes is an important step in finishing work on this project, and drivers should notice a difference to their journeys now both carriageways are fully open.
Other work will continue, which will include street lighting work – for which a 50mph limit will be in place – and fully resurfacing the road between junctions 31 and 32, which we’ve added to the programme and will be completed using overnight closures.
Some finishing off works and landscaping means scheme completion could be early in June.
Members of the public should contact the Information Line on 0300 123 5000.
Journalists should contact the press office on 0844 693 1448 and use the menu to speak to the most appropriate press officer.