The A605 Oundle Road will be widened as part of a £1.5 million scheme to ease congestion.
An extra lane will be created from the A1 slip road towards Lynch Wood, with two lanes running eastbound.
Peterborough City Council has awarded a contract to Skanska to carry out the project, but a council spokesman said the authority’s cabinet still needs to approve the widening of the road.
If the cabinet gives its approval to the project works could start in September, but a date has not been fixed yet.
It is not yet clear what disruption there will be to motorists with plans for the works to be announced closer to the time that they take place.
Funding for the project is to be split between the council and the Cambridgeshire and Peterborough Combined Authority.
The council has allocated £773,000 for the scheme, while the combined authority is providing £720,000 of funding.
A council spokesman said: “The intention is to widen an approximate 400m length of the A605 eastbound from the A1 slip road back towards Lynch Wood.
“Effectively there will be two lanes running eastbound over this section.
“There is also the possibility of a dedicated left lane into Lynch Wood but that hasn’t been confirmed yet.
“The main driver for the project is to alleviate the congestion caused by southbound traffic leaving the A1 and clogging this section of the A605.”