The changes were part of the NZ Transport Agency’s Road to Zero vision - the aspiration that no-one is killed or seriously injured in road crashes.
One of the changes affected a 190 metre section of State Highway 1, at Winchester, in South Canterbury.
The previous 100kmh speed limit was halved.
A 30km section of SH2, between Katikati and Tauranga, now has speed limits set at either 60kmh or 80kmh.
By far the longest and most substantial change made by the NZTA is the 110km stretch of SH6 between Blenheim and Nelson.
There, speed limits now never reach 100kmh, and mostly alternate between 80kmh or 90kmh.
The changes have not gone unnoticed by locals.
‘‘When’s 90[kmh] been a speed limit?’’ Seddon resident Moana Johnsen asked.
‘‘We’ve got decent vehicles that stick to the roads, and we’ve got to do 90 - 90 in an open space?’’
Ms Johnsen made the SH6 journey four times over Christmas and each time, was frustrated at the new limits.
She was worried about the overall trend.
‘‘They’ve done all these changes further down the road, the Kaikoura coast, which has been fixed up and made really nice.
‘‘But they’ve got signs up there too: 60, 80. Is the open road going to go to 80?’’
The NZTA said ensuring speeds were safe was the quickest and most effective way to prevent deaths and serious injuries.
In a statement, an agency spokesman said safe speed limits minimised the severity of crashes.
‘‘[The] agency is currently identifying roads where reviewing speed limits could make a big difference in preventing deaths and serious injuries, and where communities are calling for change.
‘‘Any proposal to drop speed limits is driven by the need to improve safety and reduce harm for everyone on our roads.’’
Director of road safety charity Brake NZ Caroline Perry said many more roads needed to be looked at - and not just state highways.
‘‘We still see at the moment a significant proportion of roads in New Zealand that have speed limits that don’t match the condition of the roads,’’ Ms Perry said.
‘‘A lot of the more rural roads that are windy, narrow, single or dual lane... are just too fast for the conditions of the road that we have at the moment.’’
She did think that was changing - and speeds were coming down, but not fast enough.
The Gisborne District Council recently signalled its intent to lower speed limits, both for Gisborne’s urban roads as well as for Tairawhiti’s rural roads.
It follows the reduction of all of Wellington’s CBD roads from 50kmh down to 30kmh last year.
But Ms Perry said it was difficult for councils - who set the speed limits for all roads which were not state highways - to change speed limits.
She wanted to see the process simplified so it could happen more quickly.
The NZTA said it was intending to make it easier for local authorities to change speed limits.