Traffic is tailing back for miles on the A45 between Rushden and Wellingborough following a rush-hour smash at the Wilby roundabout Monday morning (November 15).
At least two vehicles were involved in the shunt at just before 9am where the A509 joins the carriageway heading westbound towards Northampton.
National Highways traffic sensors show queues for about four miles back towards Rushden.
Drivers thinking of using the A4500 as an alternative route will be stymied by a road closure at Wilby for resurfacing work from 9.30am on Monday.