Speeding has been the major concern during the Christmas period with the Mittagong Highway Patrol dishing out 22 speeding infringement notices in just one day.

One incident involved a 34-year-old Victorian truck driver who was detected travelling at 154 kilometres on the Hume Highway near Alpine yesterday morning.

Mittagong Highway Patrol Sergeant Bruce Rickard said it was an extremely 'large' speeding offence.

Despite that incident, Sgt Rickard said Highland residents had been generally obeying road rules during the festive season.

"The speeds have been reasonable good but we would like it better if there were none," Sgt Rickard said.

He owed the good driving behaviour to the threat of double demerit points in operation which kicked off on December 20 and ends at midnight on January 1.

"Anything involving the loss of points is a good incentive," he said.

Sgt Rickard said not only would offending drivers face a fine or lose points but by exceeding the speed limit by a considerable amount they would face a suspension of their licence.

He said motorists travelling 30 kilometres over the limit would face a three-month suspension while those driving more than 45 kilometres would lose their licence for six months.

But Sgt Rickard said the biggest problem in the Highlands was the weather and warned motorists to drive to the conditions.

"In the Southern Highlands you get inclement weather such as fog and rain so drivers need to re-assess the conditions as they go along," he said.