Roadworks which caused traffic chaos will continue until Saturday (September 21) due to the wet weather.
A section of the A43 was closed as part of the £34m Corby Link Road scheme and it was hoped it would reopen on Thursday, September 19.
Rain has held up work and it will now re-open on Saturday morning.
A county council spokesman said: “The work on the roundabout has been necessary as part of connecting the new A43 Corby Link Road with the existing highways network and has entailed re-building and re-surfacing the roundabout.
“The three-way traffic lights are still in place and the diversion routes which had been established are also in effect.
“Works of this scale are inevitably disruptive but the county council has tried to keep any inconvenience to a minimum. The council would like to thank everyone for their patience.”
Motorists experience severe delays when the roadworks started and some said diversion signs were not clear enough.