Hunter regional manager Robert Quick said car crashes in the Stockton sand dunes were on a steady decline since the National Parks began regulating the area four years ago.

But a pattern of poor behaviour still exists with emergency services receiving regular calls during holiday periods to attend vehicle roll-overs, multi-car accidents and injuries to people.

Police investigating a head-on collision between two four-wheel-drive vehicles in the dunes on Sunday have issued an infringement notice to a Pelaw Main man, 26, for negligent driving.

Newcastle City acting crime manager Inspector Matthew Moroney said police were examining if speed played a role in the crash when two vehicles, which were coming over a crest on opposing sides of a large dune, collided about 3pm.

The Hunter Westpac rescue helicopter flew a male passenger, 17, and a male driver, 24, to the John Hunter Hospital.

An ambulance transported two other males, aged 26 and 17, to the same hospital. A Hunter New England Health spokeswoman said the 26-year-old had since been discharged while the remaining three males were in hospital in a stable condition.

Mr Quirk said motorists required a permit to operate their vehicles in the dunes and police and National Parks officers regularly conducted speed checks and breath tests.

‘‘We spend a lot of time trying to get people to understand that the same rules apply out in the dunes as on the roads,’’ he said.

‘‘Everyone who drives out there requires a permit and that information is explained clearly on that permit. There are also signs at the start of the dunes advising people to drive with caution.’’