By Georgina Mitchell
Five people, including three children, have been taken to hospital after a serious head-on crash in Sydney's west on Thursday afternoon.
Emergency services were called to The Northern Road in Luddenham, near the intersection of Elizabeth Drive, at around 3.40pm.
They found two white four-wheel-drives with significant damage, with the driver of each car trapped.
Bystanders had given first aid to both drivers before paramedics arrived.
Emergency services at the scene of a head-on car crash in Luddenham.Credit: Nine News
Police said a man was the sole occupant of one of the cars, while a woman and three children were travelling in the second vehicle.
Rescue crews worked to cut both drivers free while rescue helicopters waited in a field on the side of the road.
Steve Allam, who lives near the crash scene, told Nine News he was home with his wife when he heard a "great bang".
"My wife looked out the door and she said 'there's an accident, get me over there' because she's a nurse," Mr Allam said. "So we opened the gates... and raced over."
Ambulance and emergency services crews tended to the injured after the crash.Credit: Nine News
Mr Allam said he called triple zero and waited with one of the trapped drivers, who looked "very bad", until rescuers arrived.
A NSW Ambulance spokesman said the children, whose ages are not known, were assessed at the scene and taken to Liverpool Hospital.
The male driver was taken to Westmead Hospital by helicopter, while the woman was airlifted to Liverpool Hospital.
The Northern Road remained closed in both directions as crash investigators determined how the accident happened. It was finally re-opened just before 7.30pm.
Anyone with information on the crash has been urged to come forward.
The accident comes as police urge drivers to take care on the roads over the Christmas and New Year period, with double demerits coming into force at midnight on Thursday and ending on January 2.
So far 372 people have died on NSW roads this year, police said, which is 35 more people than this time last year.
The road toll includes four people who died since December 16, when police launched Operation Safe Arrival.
Officers will focus on speeding, drink driving, mobile phone use, seatbelt use and fatigue in the operation, which will go to January 2.
Launching the operation, Assistant Commissioner Michael Corboy from the Traffic and Highway Patrol Command urged drivers to take greater care on the roads.
"Don't let yourself or your family become a tragic statistic," he said.