The A267 and B2203 between Heathfield and Horam were resurfaced in a £1.4 million East Sussex County Council project.
The two routes benefitted from a technique specially designed for concrete-based roads, which are liable to cracking at the joints.
The road surfaces were planed down and overlaid with reinforced matting which prevents cracking and gives the road a longer life, before being coated in asphalt.
Cllr Carl Maynard, the council’s lead member for transport and environment, said: “Both of these roads carry a heavy weight of traffic and as a result were showing signs of wear and tear.
“The technique we have used prolongs the life of the road and means we shouldn’t need to carry out any more major resurfacing work for at least 10 years.
“I’d like to thank motorists and residents for their patience while we completed these works, which will result in a smoother, safer journey for years to come.”
The resurfacing, which lasted for five weeks, was carried out on the B2203 from Horam to just south of Station Road, Heathfield and the A267 at Little London from the junction of the B2203 to Heathfield.
Work on the B2203 was completed first, to ensure it was finished during the school holidays, avoiding disruption to local schools.