Car veers off bridge after NSW crash

A P-plate driver has been arrested after a collision resulted in a woman's car falling into a creek on the NSW Central Coast.

The woman, aged in her 50s, was trapped for about 30 minutes down an embankment under a bridge on the M1 Pacific Motorway at Morisset on Monday morning.

She was freed by emergency services and airlifted to John Hunter Hospital with serious injuries.

The 20-year-old driver of the other car escaped uninjured, and was arrested and underwent mandatory blood and urine tests.