Commuters will be able to use the A43 north of Northampton after it was reopened by the emergency services.
It follows a three-vehicle accident at about 8am that closed the A43 in both directions between Northampton and Kettering, a nine-mile stretch of road.
A police spokeswoman said that, although the scene of the accident was confined to near the Sywell/Holcot roundabout, the closure was necessary to stop HGVs getting onto the carriageway as they would be very difficult to turn around.
Police said the road was reopened at 1pm.
A fire service spokesman said: “Two casualties were released by fire service. One was conveyed to hospital by air ambulance, one was conveyed to hospital by land ambulance.
“Crews used hydraulic cutting equipment, long board, and glass management equipment. Crews attended from Moulton, The Mounts and the technical rescue vehicle from Mereway.”