National Highways has signed a deal with four contractors to work on the £1.3bn upgrade of the A66.
The cross Pennine route is one of the busiest A-road sections in England with many Scottish hauliers using it to crisscross the UK.
Dualling the remaining single carriageway sections between Penrith on the M6 and Scotch Corner on the A1(M) will be Balfour Beatty, Costain, Keltbray and Kier.
Work is expected to begin in 2024 and take five years.
