Four accidents in 12 hours on Central Coast Highway, M1

11AM: Five people have been rushed to Gosford Hospital, after a two car smash in East Gosford this morning.

Paramedics have to free one of the people trapped inside, after the vehicles collided on the intersection of the Central Coast Highway and Frederick Street after 9am.

Four others suffered minor injuries, and were taken to hospital in a stable condition.

The road's since cleared up there.

It follows a multiple car crash on the M1 at Alison this morning, which left one southbound lane closed and traffic queues of 10 kilometres around 9am.

A southbound lane was also closed this morning, after a four car accident near Jolls Bridge. No reports of injuries coming out of that incident.

THIS MORNING: The M1 had to be closed southbound at Morisset for about four hours as emergency services responded to a serious truck crash (photo above).

A B-double crashed into the back of a slow-moving line marking truck near the Mandalong Road exit just after 11pm last night, blocking all southbound lanes.

It caused a large oil spill, with about 400 litres of diesel covering 300 metres of road.

Thankfully both truck drivers weren't injured.

Both returned negative breath tests.

The freeway was re-opened to traffic just after 3am.