Video: Workmen begin repairs to the hole on Tuesday
The A690 in Sunderland is due to reopen by Friday night after torrential rain caused an enormous hole to appear by the roadside.
It was threatening the collapse of the westbound carriageway.
Repairs were delayed by a burst water main, which Northumbrian Water was due to finish fixing on Thursday morning.
The road, close to the junction with the A19, has been closed since Tuesday.
Councillor James Blackburn, Portfolio Holder for City Services at Sunderland City Council, said: "The A690 is one of the busiest roads into the city. We're doing all we can to minimise disruption to motorists by getting the work completed as quickly as possible to allow it to re-open.
"We hope to be on site to start filling the hole as soon as repairs to the water main are complete but the concrete has to set properly before we can open the road fully."
Diversions remain in place for south-westbound traffic, via the A19 north/A183 Chester Road to Shiney Row/A182 to Houghton-le-Spring. Stoneygate remains open.