Oakham's £11.6m bypass has been opened, two months ahead of schedule.
A fleet of ceremonial vehicles were the first to use the road
A group of primary school children cut the ribbon giving the green light for traffic to use the three-mile long road.
It links the A6003 to the A606 and incorporates a new railway bridge, so motorists can avoid a level crossing which was an accident black-spot.
The road aims to ease traffic congestion as well as improving safety for pedestrians and cyclists.
Rutland and Melton MP Alan Duncan said: "It's going to make a lot of difference to Oakham.
"I think it will lead to a redesign of the centre of Oakham, so that it can keep its character as a market town, so people can walk around and not bump into a 10-ton lorry."