The Dunedin City Council changed the speed limits for safety reasons, following concerns from the local community that the existing speed limits were neither safe nor appropriate given the use of the road environment.
Otago Peninsula Community Board chairman John Bellamy said the board was ''extremely pleased'' the lowered limits were approved.
''The key is having speed limits appropriate for areas such as narrow back roads, and anything to make these roads safer has to be a good thing.
''We were all pretty aware that some speeds were totally inappropriate for the area.''
Dunedin area road policing manager Senior Sergeant Phil McDouall said police welcomed any initiative that could potentially reduce road trauma.
Over the years, there had been many crashes on Peninsula roads resulting in fatalities and serious injuries, he said.
''These roads are often used by tourists who mostly drive large camper vans and are not familiar with the area.''
However, lower speed limits were just one ingredient in the mix that created safer roads.
''Drivers also need to be mindful of driving to the conditions and other critical factors that they can control, including driving behaviour, manner of driving, alcohol and wearing a safety belt.''
A large part of the area where speed limits are changing will become a study area as part of a national review of how speed limits are set. It will be identified with special signs on all entry points to the study area.
The safer speed area will have a maximum speed of 70kmh, except for a small section near Larnach Castle, which will become a 50kmh zone.