A bottleneck occurred on the Princes Highway southbound through Albion Park Rail as cars wound their way to their southern holiday destinations.

Officers from Wollongong and Lake Illawarra police area commands were out in force targeting speeding, drink-driving, seatbelt and other traffic offences in the first days of NSW's annual road blitz Operation Safe Arrival.

Lake Illawarra Acting Inspector Martin Church urged motorists to stay calm when faced with traffic congestion.

"As soon as you get public holidays the traffic just builds up on the Princes Highway," he said.

"I'd urge motorists to have patience, to keep to the speed limit and to try not to get frustrated - there will be delays, but they won't be for that long."

By late yesterday, 16 people had died on the nation's roads this holiday season.

One of the fatal crashes occurred on Mt Ousley Road on Sunday afternoon, when a 79-year-old woman died and her husband, 80, was seriously injured.

Meanwhile, drivers in NSW are the focus of police pleas to slow down and smarten up, with the state claiming all five of the nation's road deaths on Boxing Day.

A 14-year-old Fijian boy, who lives in ACT, was also fighting for his life in hospital last night.

The teenager was one of five family members who were taken to hospital following the single-vehicle crash six kilometres north of Holbrook in NSW.

A husband and wife, both aged 70 and visiting from Fiji, also died when the seven-seater Nissan Patrol left the Hume Highway and rolled about 6.55am yesterday.

The teenager suffered head injuries and was airlifted to a Canberra hospital in a critical condition while a 67-year-old woman was airlifted to Melbourne with possible spinal injuries. She is in a stable condition.

The driver, a 44-year-old man, his 45-year-old wife and her 40-year-old sister received minor injuries.

The crash survivors are from Chisholm in ACT and all are from the same Fijian family.

In another fatal accident at 6.50am, police were called to a two-car collision at Marsden Park in Sydney's north-west.

A 27-year-old man was found dead at the scene while a 24-year-old man from Lithgow, driving a Mitsubishi Magna, was taken to Westmead Hospital.

He underwent mandatory blood tests and further treatment for head and facial injuries.

Police allege the 24-year-old was an unaccompanied learner driver.

Later in the day two men died less than an hour apart after their cars hit trees in separate accidents.

A sedan left the road on Murray Street at Abernethy in the Hunter Valley and struck a tree about 2.30pm, a police spokeswoman said.

The driver, whose age wasn't known, was discovered by a passing motorist. The injured man died at the scene.

It followed a similar accident involving a tree at 1.45pm at Hargreaves, in the state's Central West, where a passenger died.