Parliament has unanimously passed legislation to fix a legal blunder that would have made speed limits set by local councils and authorities invalid.
Transport Minister Simon Bridges said, since 2004, some speed limit bylaws had inadvertently expired following changes in legislation.
He said the Land Transport (Speed Limits Validation and Other Matters) Bill, which passed through all its stages last night, would retrospectively validate those limits.
"The bill corrects some technical legal issues and the powers available to make some speed limit bylaws, and the review process for local government bylaws.
"This bill ensures these bylaws and the speed limits made under them remain valid, and therefore enforceable."
Mr Bridges said it was not known how many drivers or infringement notices may have been affected but those notices would now be made valid.
Local Government Minister Paula Bennett said some councils had failed to renew their speed limit bylaws following changes in legislation.
"After it was brought to officials' attention that some councils failed to renew their speed limit bylaws, the Government was made aware of a potential problem with some speed limits set from 2004 onwards," Mrs Bennett said.
She said confusion amongst some councils about the legislative framework arose after changes were made to local government legislation in July 2002 and June 2006, as well as transport legislation in April 2004.
The legislation confirms local councils and other road controlling authorities (RCAs), such as the New Zealand Transport Agency, have the legal power to set speed limits.
"For the avoidance of doubt, this retrospective legislation validates the speed limits set by councils and other RCAs since 2004."
The local council which drew attention to a legal blunder which had made some speed limit bylaws and all speeding tickets invalid said it was pleased with Parliament's response.
Mr Bridges said officials became aware last month after the Kapiti Coast District Council became concerned its speed limit bylaw had expired.
Council chief executive Pat Dougherty said the council misinterpreted how often its speed limits bylaw, passed in 2005, needed to be updated.
"This is a technical and complex area of the law, and we understand our concern that many other councils might be in the same position is valid," he said.
Mr Dougherty said the council believed the bylaw had a 10-year life, when in fact it was valid for five years with a two-year period of renewal.
"We didn't appreciate the full implications of the bylaw expiring, initially believing we would simply be unable to set new speed limits until a new bylaw was adopted.
"On this basis, we prioritised other work ahead of updating the bylaw."
He said while the council was not happy it made a mistake, it was pleased the situation had been clarified for all councils.
Mr Dougherty said the council was currently consulting with the public on an updated bylaw.