The A358 at Bishops Lydeard is set to close overnight later this month for the installation of a new underpass.
The work is part of a major scheme to build a new roundabout and is being delivered by contractor SWH Civils on behalf of Taylor Wimpey as part of a legal agreement linked to the construction of new homes in the village.
Somerset County Council said work remains on schedule but the programme has been amended with road closures now starting on Tuesday 28 February from 19:00 to 07:00 to allow work on the new underpass to be completed safely.
The work is expected to take two nights though Somerset County Council have warned that, depending on weather and other factors, it may be extended until the end of the week.
The A358 and Greenway will also close for the new road surface to be laid.
Details of this phase of work will be confirmed nearer the time.