A young man speeding at 174 km/h because he was "late for lunch" and a senior citizen who crossed the centre line 10 times are two examples of some appalling driving in the holiday break.

Police say the number of reported crashes and motorists dobbing in others for dangerous driving has fallen from previous holiday periods.

Calls to police from concerned motorists about others' driving have fallen 10 per cent over the past three years, according to police figures.

Crashes reported in that time fell 22 per cent.

Superintendent Paula Rose, national road policing manager, said it was a sign travel behaviour was improving.

"We can't be complacent but all the information we have presents a better picture," she said.

"The bottom line is that road safety is everyone's responsibility and not just the police's ... We want every journey to be a safe one."

One caught this Christmas was a 21-year-old Bay of Plenty man driving at 174 km/h. He told the police he was "running late for lunch".

In another hair-raising example, an elderly woman was seen crossing the centre line on corners more than 10 times on the coastal road between Waihi and Whangamata. Oncoming motorists were forced to take evasive action twice.

"Given the weather and the heavy traffic volumes, this was a recipe for disaster and we're very fortunate a tragedy didn't occur," said Senior Sergeant Jeff Penno, Waikato's acting road policing manager,

He said 35 crashes happened in the Waikato on Tuesday - more than a third of which involved single vehicles in the Hauraki-Coromandel area.

Speed and alcohol are key focus points for the police over the holidays but they have urged drivers to consider their road awareness and courtesy.

"We don't want drivers to speed but we also don't want the classic 'Sunday drivers' out there in peak traffic unnecessarily holding up traffic either," Mr Penno said.

He warned motorists to start travelling earlier as roads to Thames, Whangamata and Whitianga would get busier in the lead-up to the new year.

Sergeant Mike Owen of the Western Bay of Plenty highway patrol said that despite warnings of a hard line on motorists driving more than 5 km/h over the limit, 12 had been stopped for driving at more than 20 km/h over.

"We've seen the ads," he said. "It's that simple: speeding causes crashes; we need to slow down."