Drift-In Lunch Bar, Newport Auto Electrical & Air Conditioning, Tumu Frame & Truss, Norwood and Beard's Environmental will all remain open and people can still enter their buildings.
However, Newport Auto Electrical & Air Conditioning will have a different entry point at times over during the works. Signs will be in place to direct customers to alternative access.
The other roundabout on Maraekakaho Rd is designed to improve safety for vehicles accessing Irongate Rd.
The roundabouts are part of a raft of transport projects, including extending cycle paths and trails.
This week work also started to build a new trail at Waimarama Rd. All work will take place off-road so there will be no traffic disruptions.
On Napier Rd, cycle lanes are being built between Havelock North and Te Ara Kahikatea, and are expected to be finished in March.
This will include an off-road shared concrete path on the eastern side between Thompson Rd and Romanes Dr that will form a loop.
"These are exciting projects that will improve safety and accessibility, and create more opportunities for people to walk and cycle," Kerr said.
Meanwhile, work continues on other road and footpath safety projects including the SH51/Waipatu upgrade, building a shared pathway on School Rd, Clive, and ongoing bridge strengthening projects, as well as maintenance of the rural road network, including ongoing resealing work.