A four-vehicle pile-up sparked huge queues on the A45 between Wellingborough and Northampton during Thursday's morning rush hour.
Highways England reported delays of up to 50 minutes as traffic was snarled up over a five-mile stretch westbound all the way back past the A509 at Wellingborough.
Two more bumps were reported in the queues adding to the hold-ups.
The accident was reported just past the Grendon turn-off with one lane blocked while emergency services dealt with recovery work on.
One commuter reported taking 35 minutes to cover a two-mile stretch between Great Doddington and Grendon.
And the weight of traffic caused more snarl-ups on the A4500 old Wellingborough Road as drivers tried to find alternative routes