Motorists are being urged to exercise extra patience and caution at intersections after the new give way rules were introduced on Sunday.
Vehicles turning right at intersections must give way to traffic from the opposite direction that is turning left, under the rules which came into force at 5am.
Drivers at the bottom of T-intersections have to give way to all traffic turning right from the other road.
The Transport Agency (NZTA) has spent more than $1 million on an awareness campaign in the 10 days leading up to the changes, and is asking drivers to be careful and courteous at intersections.
Clive Matthew-Wilson of car review website dogandlemon.com says the agency should have started its campaign six months ago. He believes there could be more intersection crashes because motorists are confused.
NZTA spokesperson Andy Knackstedt disagrees, saying if the advertising campaign had been started too early, people would have thought the rule had already changed and would have begun to apply it too early.
Automobile Association spokesperson Simon Lambourne believes awareness is high. "The community and motorists have been discussing this since January," he says.
The Transport Agency says that, given there is a crash at intersections every 30 minutes, people should not assume such crashes on Sunday are because of the new rules.