The A690 road westbound has been re-opened after it was shut to traffic at Houghton Cut following last week's storms.
Huge mounds of snow had gathered on the hills next to the westbound carriageway, with council bosses opting to close the stretch of road in the interests of safety.
There had been fears that any melting snow could fall onto vehicles below and cause accidents.
Officers from Tyne and Wear Fire and Rescue service have been trying to dislodge the drifts over the past few days, without success.
But traffic is now moving again on the road this afternoon after the outside lane was re-opened.
The inside lane remains closed.
The North East Live Traffic account tweeted: "A690 Houghton Cut is now reopened southbound with lane one closed along the length of the affected area #Sunderland."
The westbound side had been shut from the junction with the A19 at Doxford Park since Friday, with drivers having to take alternative routes.
A 100 metre stretch of one metre high water filled barriers is being put in place to separate the two carriageways and limit any snow from the rock face falling into the closed inside lane.
The situation will continue to be monitored on a two-hourly basis.
Councillor Michael Mordey, portfolio holder for city services, said: “The A690 is one on the main arterial routes into and out of the city and we understand the inconvenience the westbound carriageway's closure has brought to the many thousands of people who use it on their daily commute and would like to thank them for their patience.
“Public safety has to be a priority but we have been working with our partners in the police and the fire service since Friday to reopen it to the traffic at the earliest possible opportunity.
"This has included two attempts by Tyne and Wear Fire and Rescue Service to dislodge the overhanging snow drifts which unfortunately were unsuccessful.
“We believe we have now found a compromise that will allow us to go ahead with reopening the outside lane safely while we continue to monitor the situation.”