The 110 million pound 5.5km long dual carriageway has been built to ease traffic between Newton Abbot and Torbay.
The opening of the road had been kept a secret to avoid any problems caused by hundreds of drivers wanting to be the first on the road.
The scheme started in 2012.
Two men missing after entering sea
Huge emergency response in Budleigh Salterton
Students take over Radio Exe
Christmas Day special from Xpression FM
Work to start on major Tavistock Road improvements
£45 million scheme moves to phase 2
Last night of the Christmas Proms - REVIEW
Bournemouth Symphony Orchestra at the Great Hall
Christmas snow possible on Dartmoor
That's despite no white-Christmas predicted
