Motorists are being warned to expect disruption as the next phase of an £11.6m road maintenance scheme begins.
Somerset County Council is in the middle of a substantial programme to upgrade traffic lights and pedestrian crossings across the county.
Work on lights and crossings in Taunton was completed in the autumn, with a further phase of work currently under way at various locations in Yeovil.
The council has announced dates for Shepton Mallet and Wells in late July.
Work in Frome is expected to be finalised later in the year.
The sole element of the programme within Shepton Mallet will be upgrading the junction of the A361 Fosse Lane and Charlton Road, near the Thatched Cottage Inn.
Work on this junction will begin on 21 July and is expected to last until October, the Local Democracy Reporting Service (LDRS) said.
Most of the work in both Shepton Mallet and Wells will take place under temporary lights, though there may occasionally be short evening or overnight closures.
Access for residents and businesses will be maintained throughout.
The Frome leg of the work is at the planning stage and is expected to start in the autumn or winter of 2022.