They are among about 20 proposed changes across the South Island, covering just under 20km of more than 5000km of state highways, and NZTA is now consulting with local communities on the initiatives.
The proposed changes in Otago are centred on Waitati, Outram and Roxburgh.
On State Highway 1 at Waitati, residents raised concerns about a curve beside the settlement, where driver visibility and sightlines could be limited.
Nearby homes, bus stops, a shop across the highway, and an intersection where people and vehicles regularly turn on to and off the highway also created safety concerns.
NZTA has proposed a speed reduction from 100kmh to 80kmh, between Double Hill Rd and southwest of Harvey St.
It is expected to make journeys through the area 3 seconds longer for cars (2 seconds longer for heavy vehicles), but it was estimated injury crashes in the area would be reduced by 20%.
In Outram, a speed reduction of 100kmh to 80kmh is proposed on SH87, from the Taieri River Bridge to the 50kmh speed zone in Holyhead St.
In recent years, there has been a growth in activity and housing on the approach to Outram, and a slower speed limit was seen as a way to address local access and safety concerns raised by the community.
The change was expected to add 3 seconds to the trip through Outram, but it would reduce the number of injury crashes in the area by 20%.
On SH8 north of Roxburgh, a reduction in speed to 60kmh has been proposed, down from the present 80kmh signpost to an area north of Selkirk Pl.
It has also been proposed to extend the 50kmh speed zone from north of Selkirk Pl to Edinburgh St, in Roxburgh.
It aimed to address safety concerns raised by the community, about the increasing housing and the need for better business access in the area.
Travel time would be extended by 8 seconds for all vehicles, and it was expected injury crashes would be reduced by 36%.
In Southland, there is a proposal to change the speed of a section of road on SH94, north of Te Anau, between Upukerora Rd and Rocky Ridge, from 100kmh to 80kmh; and from Upukerora Rd to the edge of the Te Anau township from 80kmh to 60kmh.
The proposed changes mean it would take all traffic about 10 seconds longer to drive through.
The road is the main route to and from Milford Sound, and the increasing number of rural residential and lifestyle blocks along that stretch of road means there are more people walking and cycling, and more vehicles turning at intersections and private accesses.
The reductions aimed to reduce the likelihood and severity of crashes, particularly for vulnerable road users.
Growth in the popularity of Colac Bay/Oraka as a holiday and surfing spot has also prompted NZTA to reduce the speed on SH99 through the township, from 100kmh to 80kmh.
The change was expected to make the journey through Colac Bay, about 3 seconds longer for cars and 2 seconds longer for heavy vehicles.
Also on SH99, NZTA has proposed reducing the speed in Riverton, between Shrewsbury St and Thames St, from 70kmh to 50kmh.
The stretch of road passes through a developing area with increasing activity, including more people walking and accessing nearby properties.
It was expected to take 6 seconds longer for all vehicles to travel through, and reduce injury crashes by up to 24%.
An NZTA spokesman said if the speed limit changes went ahead, they were estimated to cost about $50,000 each.
The costs included planning, road signs and markings, installation costs, overheads, and consultation and administration costs.
But they may vary depending on whether it required basic signage, or electronic signage for an Intersection Speed Zone, for example.
Consultation closes at 5pm on August 25, 2026.
