The M1 motorway is likely to remain closed northbound throughout the morning rush hour following a multi-vehicle collision early on Monday (July 18).
The northbound carriageway reopened at 7am.
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All emergency services are working at the scene and Northamptonshire Police tweeted that the road was “expected to remain closed throughout the morning”.
In a tweet, the force said: “We would ask all drivers to avoid the area and to seek an alternative route.
“Thank you for your patience and support whilst we deal with this incident."
The M45 is also closed eastbound at Dunchurch.
National Highways has issued details of diversion routes for M1 traffic using the A5 and A45.
No information has been made available about injuries or number of vehicles involved.
Congestion is back to junction 20 on the M1 and junction one on the M6 as traffic struggles to join the motorway. Sensors also showed queues growing on the A5 through Crick before 8am.
UPDATE: National HIghways tweeted at around 8.45am: “All lanes are now open on the M1 southbound between J18 Daventry and J16 Northampton following a serious collision. Please allow extra time if travelling in the area as delays of 20 mins and approximately two miles of congestion remain.”