The start of work follows the public information event held in August where drivers were invited to find out more about the plans, between junction 56 and 57 of the A14 near Ipswich.
Most of the improvement work will take place overnight and is planned to be completed by the end of February 2016. There will be some overnight lane closures for preparation work starting on 23 November.
Aran Nugent, Service Delivery Team Leader at Highways England, said:
The A14 at Orwell Bridge is a vital route and we are committed to improving safety and reliability for the thousands of drivers who depend on it every day. This is why we will be reducing the speed limit to 60mph, installing average speed cameras, improving road markings and signing and improving the signing around the service area.
We have planned this work carefully to minimise the inconvenience to road users, by carrying out work overnight when traffic flows are lowest, and will suspend work during the Christmas period, but I would urge motorists to plan ahead and allow extra time in case of any delays.
Most of the work will be carried out overnight involving lane closures between junctions 56 to 57 with some minor work taking place on the verges during the day. The westbound slip road at junction 56 will be closed overnight, from 8pm until 6am, and traffic will be diverted to junction 55 and re-join the A14 eastbound to exit at junction 56.
More details including dates will be announced in the East of England roadwork summary.
There will be full closures of the A14 between junction 55 and 58 towards the end of the scheme and more details will be announced.
The work is dependent on suitable weather conditions, and dates may be subject to change.
Members of the public should contact the Highways England customer contact centre on 0300 123 5000.
Journalists should contact the Highways England press office on 0844 693 1448 and use the menu to speak to the most appropriate press officer.