The public has six weeks to have its say on plans to dual another section of the A47 through Cambridgeshire.
The 1.6-mile stretch - between the villages of Wansford and Sutton west of Peterborough - is near where the A47 meets the A1.
The work is expected to cost between £50m and £100m, and the new road open by the spring of 2021.
A public consultation was launched on Tuesday - and will run until 29 October.
Claudia Wegener, senior project manager for the A47 programme for Highways England, said the plan was to start work in the autumn of 2020, with the new dual carriageway open to traffic from the winter of 2021.
A timetable for £300m of improvements to the A47 was set out in October 2017.
Tom Cornwell, area manager for the Road Haulage Association, welcomed the consultation, describing the A47 as "horrendous".
"If it all goes well, it will improve journey times, reduce collisions and reduce congestion," he said.
Michael Sly, a farmer from Thorney, said the upgrade would have a "tremendous effect" on the economy of the area.
"It can be a very slow and unsafe, with certain sections unfit for purpose for modern transport," he said.
"The whole route needs upgrading for the people who live here and for the prosperity of the region."