Police say the lanes were closed at junction 30 near to Bamber Bridge after a lorry crashed into the central reservation yesterday evening.
Tailbacks were reported as far back as junction 32 near Broughton and drivers were warned to plan extra time for their journey.
Last night the M6 southbound was blocked after a lorry went into the central barrier.
Several other vehicles were involved in the accident which happened just after 9pm on Wednesday.
One lane remains closed as at around 10am.