"I think what is happening is people are being a lot more patient and even when they know someone is still going on the old rules they're still being reasonable about it."
He said there had been no big increase in crashes that he was aware of. "It's gone quite well. The police are out there handing out leaflets [with the rule changes] and they have been told to use their discretion and to educate people."
Mr Macdonald told the Herald drivers appeared to be thinking about their actions.
"They're not on automatic pilot, they're actually thinking 'am I actually doing the right thing here?' so that's been excellent for us."
He hoped the driving behaviour would continue in the days ahead when there was less emphasis on the changes.
His message to drivers was: "Just because it gets embedded in don't stop being courteous [and] don't stop thinking about what you are doing when you're driving."
Acting national road policing manager Rob Morgan said it appeared to be a normal Sunday for traffic police nationally.
He said police were not expecting a big increase in crashes.
"The experience when they did this in Australia was people were more cautious and it went smoothly."
It would take a few months of analysis to determine how many of the accidents yesterday happened at intersections and what caused them, he said.
Drivers were hesitant and courteous at two busy Auckland intersections observed by the Herald yesterday.
The new rule gained overwhelming compliance during an hour-long inspection of the Mt Roskill junction of May Rd with Mt Albert Rd.
Only one breach of the new rule occurred during the inspection, between 2pm and 3pm, although many drivers turning left from Mt Albert Rd hesitated before claiming their new right of way.
It was in contrast to a Herald survey on a week-day afternoon in late 2008, which found 25 breaches in just one hour.
Meanwhile, only two of 24 drivers failed to obey the new rule at the Rocklands Ave intersection with Dominion Rd .
However, the frantic search for eye contact with the opposing driver and nervous smiles of many after making it through indicated that the rules will take some getting used to.
The unaccustomed wait was too much for one man, who after correctly giving way several times ploughed ahead with the old rules, further bewildering the opposing driver.