Two lanes on the M1 Northbound between J15 - J15A are currently closed due to a collision.
The collision has taken place on the M1 before J15A, A43.
It has been reported that two cars and two lorries are involved.
There are currently delays of 60 minutes above the usual travel time on approach to this incident.
It is not yet known if anybody has been injured.
UPDATE 14:06: All lanes at J15a have re-opened and traffic's starting to ease.
Reports say traffic is still heavy on the A5 at the A508 (Old Stratford) and on the A509 Newport Pagnell and Northbound to Emberton