Motorists will face diversions near Boxford and in Layham, near Hadleigh, next week due to work on electricity power lines.
Brick Kiln Hill, leading to Stone Street near Boxford, will be closed for a month from February 4 by National Grid.
The company says signs are already in place to alerts drivers, and a diversion route will be clearly marked.
A spokeswoman for the company said: “We closed the road last year during the first phase of work, so local people will be familiar with the route.”
The other road closure planned is Rands Road, Layham, on February 19 for a month.
The spokeswoman said: “We’ll be writing to affected residents shortly. The road closures are part of our work to rewire the existing overhead electricity lines.”
National Grid has announced Alphamstone as the location chosen for essential cabling equipment.
The equipment is needed to join the section of underground cables through the Stour Valley to an existing overhead power line.
The company is upgrading lines running from near Ipswich to Twinstead and has been consulting with residents for more than three years.