About 9.30pm on Friday, September 27, officers from Mid North Coast Police District and Traffic and Highway Patrol were on scene of a two-vehicle crash on the Pacific Highway near Thrumster.

A female driver was arrested and charged with mid range PCA and will face court at a later date.

As a result of the collision, lane one of the Pacific Highway had been closed to allow for emergency services to clear the scene. All vehicles warning lights were activated.

Then, at about 10pm, a Holden Cruze was travelling northbound when it collided with the rear most marked highway patrol vehicle at the scene.

The driver, a 45-year-old Greenacre man, underwent a roadside breath test which allegedly returned a positive reading.

He was taken to Port Macquarie Police Station where he underwent a breath analysis which allegedly returned a positive reading of 0.180.

He was charged with high range PCA and granted bail to face Port Macquarie Local Court on Wednesday, October 23.

No one was injured.

Far Northern Region Traffic Tactician, Inspector Peter McMenamin, said this incident is a timely reminder of how decisions behind the wheel can have potentially devastating consequences.

"This incident has seen two drivers get behind the wheel while under the influence of alcohol which has resulted in two separate collisions. This is unacceptable - to think about how many innocent lives could have been impacted," Insp McMenamin said.

"Driving under the influence of alcohol lowers your reaction times and your ability to make decisions in a timely manner - we're lucky there were no serious injuries following these crashes.

"When driving past a collision scene, please slow down. The flashing red and blue lights are warnings for a reason.

"With school holidays in NSW starting from today and the October long weekend fast approaching, police will be out in force making sure our roads are safe."