The A360 north of Salisbury has reopened unexpectedly after the closure to install power cables.
The road had been expected to open in mid-July, but has opened already and the work appears to be complete.
Salisbury Radio had contacted the project earlier this week to enquire about an end date and the progress of work. They responded on Wednesday (3rd July), "We can't share a specific date with you right now but will be able to share more information towards the end of this week going into early next week.
The work was part of the preparations for the A303 Stonehenge Tunnel project, upgrading high voltage power to the area.
The closure of the five-mile stretch of road will caused extra traffic to use other routes in and out of the city, including the A345 and the A36.
At times, the closure has brought Amesbury to a standstill and queues into Salisbury on the A345 Amesbury Road have queued back past highpost.
It has also had a knock-on effect, when combined with other roadworks, in a significant reduction in footfall and trade in Salisbury City Centre.