A "refreshed" double demerits campaign, launched yesterday by minister for roads Duncan Gay and minister for police and emergency services Stuart Ayres, is set to ensure drivers think twice before breaking the rules.

The TV, radio and online messages - which feature a driver being questioned by two identical policemen - will be used in NSW every holiday period.

"It urges us to think twice before breaking the road rules, or risk facing double the consequences," Mr Gay said.

"We know double demerits are an effective road safety initiative - we've reduced deaths on our roads during holiday periods by a third since they were introduced."

"This is hundreds of lives saved and many families spared the loss of a loved one, which is why we've refreshed the double demerits campaign."

Operation Slow Down - a high-visibility traffic operation to combat the road toll - started at 12.01am today and runs until 11.59pm on Monday.

Double demerits will be in force during the period and police have warned the consequences will be severe for those who do the wrong thing.

Police have described the weekend as a "perfect storm" on the roads, with major sporting events including the NRL grand final and the end of the school holidays expected to increase traffic volumes.

NSW Police Force deputy commissioner Catherine Burn said the need for vigilance was high this weekend.

"We expect to see a large increase of motorists taking to the roads to enjoy these events and the warmer weather, however, this always brings an element of risk," deputy commissioner Burn said.

"Speed, tiredness, seatbelts, drink-driving and distraction - combined with more motorists on our roads can be deadly."

Mr Ayres said motorists could expect to see increased high-visibility patrols, random drug and alcohol testing, and speed enforcement.

"Last year seven people lost their lives over the October long weekend, which was the highest fatality total for this long weekend since 2010," he said.

"This is why we're reminding drivers to be extra careful on the roads over the next few days and get home safely."