Works to install a new concrete barrier between junctions 24 and 25 of the M5 will start next week.
The works around the Bridgwater area will take place in two phases.
Phase one will begin on 12 December and will involve drainage and barrier works to the verges. Work will also be undertaken to prepare the hard shoulder to receive running traffic for the phase two works.
Phase two will begin on 4 January and involves constructing 1.7km of concrete barrier along the central reserve.
Ancillary works include drainage and bridge pier protection with the job due be completed by 19 February.
During both phases of the scheme, traffic management will be in place for approximately 2.5 miles.
Highways Agency project sponsor Dave Frampton said: “These works will help improve travelling safety and mitigate the risk of cross over crashes.
“The Highways Agency will make every effort to ensure that any disruption to road users is minimised throughout the scheme.”