Eurovia will take North Kent, defined as the districts of Canterbury, Gravesham, Maidstone, Swale, Thanet and Tonbridge & Malling.
Tarmac has the contract for South Kent, covering Ashford, Dartford, Dover, Sevenoaks, Shepway and Tunbridge Wells.
The work for Kent County Council will be carried out in phases, with no work carried out between December and February each year.
Work starts on the first phase this month at 55 sites across the county, with completion in November. Phases two and three will follow on in spring 2013.