Gloucestershire County Council has given its formal backing to Highways England’s route options consultation for the A417 Missing Link.
The council supports Highways England’s preferred route, Option 30, but would not object to Option 12 if that is subsequently taken forward.
The A417 runs between Gloucester, Cirencester and Swindon and bottlenecks along a stretch of single-carriageway through Birdlip.
There has been a number of fatal crashes where the road becomes a single carriageway from the Air Balloon roundabout, through Birdlip and Nettleton Bottom, to the Cowley roundabout.
The accidents, and congestion, has led to repeated calls from campaigners for a bypass to be built.
In 2014, it was reported there had been 340 casualties on the road in 15 years – and recently there was a serious crash leaving one man, aged 67, in a critical condition.
Concerns were raised that the preferred option will lead to an increase in noise and air pollution, carbon oxide emissions, and could add additional congestion in Stroud, Cheltenham and Gloucester.
A Highways England report said: “A 3.4-mile surface route following the alignment of the existing A417 at Crickley Hill with less of a slope. A new section of road will be built through Shab Hill to the east of the existing A417, re-joining the existing road near Cowley roundabout.
“Option 30 would include two new junctions – one at Shab Hill and one on the existing A417 close to Barrow Wake with a link road in-between. There would be three lanes of carriageway going up Crickley Hill and two lanes coming down.”