Seven die in horror 48 hours on NSW roads

Seven people, including three from one family, have died in the past 48 hours in a shocking period on NSW roads.

Sydney parents Darren and Susana Milne and their 11-year-old son were killed on Sunday when their car hit a tree at full speed on the Central Coast.

The Milnes' other son, who is seven, survived the smash at Berkeley Vale and is in hospital in a critical condition.

Two cyclists have died in the past two days while an 84-year-old and 70-year-old man died from injuries suffered in separate crashes.

Traffic and Highway Patrol Inspector Phil Brooks conceded the number was certainly high.

"There have been a number of tragic and sad events that provide a timely reminder to all road users to share our roads safely," he said.

Thirty-seven people have died on NSW roads this year, up four compared to the same time in 2014.