Civilian vehicles will now be required to slow down to 40km/h when they see emergency service vehicles with flashing lights on the roadside.
Infrastructure and Transport Minister Michael Ferguson said the whole point of the new law was to help allow services to focus on attending an emergency more efficiently.
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"We need road users ... to be more aware of their duty of care as drivers to people who will be responding to any emergencies on the sides of roads," he said.
Mr Ferguson said there will be financial fines that are being reviewed for those who don't comply with the new law.
"They will be significant fines," he said.