The second young person died on Sunday after the crash near Mudgee on Friday night.

The 16-year-old male had suffered serious head injuries and died in Westmead Hospital on Sunday morning.

Earlier a 14-year-old male passenger had died at the scene on the Wollar Road at Munghorn.

And on Friday a 45-year-old man died after his vehicle was allegedly hit by a passing truck at Manildra near Orange.

Police called the two incidents a tragic start to the Queen's Birthday Long Weekend.

The crash near Mudgee had come hours after police told of a concerning increase to the region's road toll compared with the previous year.

Deaths on western NSW roads had reached 32 people by Friday at 6am, up from just 22 at the same time in 2015.

The figures led the state's police and highway patrol officers to once again launch Operation Stay Alert over the long weekend and to plead with motorists to take more responsibility behind the wheel.

"As of this morning we're 10 higher than we were last year," western region traffic tactician Inspector Peter McMenamin said on Friday.

At the weekend his safety warning was repeated by police at the highest level.

Traffic and highway patrol commander, Assistant Commissioner John Hartley on Sunday urged drivers to slow down on the roadways with speeding infringements up by 743 from 2015.

"Speeding is a risk that can lead to a tragedy," he said.

"Drivers need to slow down and remain alert while on the road.

"I urge everyone to take care, drive responsibly, respect other motorists and obey the road rules," Assistant Commissioner Hartley said.

Fourteen-year-old Jackie Omalveney was the passenger in the vehicle who died at the scene near Mudgee.

Jackie's family on Saturday set up a GoFundMe page to help his mother raise funds for his funeral.

The page shared photographs and messages from people who have donated. On Sunday morning it had raised over $3000.

Police from the Metropolitan Crash Investigation Unit are continuing to investigate the circumstances surrounding the incident.

A report will be prepared for the Coroner.