Drivers are being advised to avoid the M1 through Northamptonshire after a vehicle fire blocked two lanes on Wednesday lunchtime (May 25).
National Highways says there are six miles of queues southbound between between junction 16 to junction 15A near Northampton.
Sensors are also picking up long tailbacks northbound as traffic is slow past the scene.
A spokesman said: “Northamptonshire Fire & Rescue are at the scene along with our traffic officers but congestion is likely to continue at least until late-afternoon please allow extra time for your journey.”