Dunedin City Council – Kaunihera-a-rohe o Otepoti

Three Mile Hill Road

Last updated: 19 Oct 2026 12:05am

We're proposing changing the speed limit on a section of Three Mile Hill Road from 80 km/h to 60 km/h to improve safety for everyone who uses the road and better reflect the safety risks on this section of road.

We want to hear your views on the proposed change. Tell us what you think before public consultation closes at 5pm on Monday 30 November 2026.

Background

The current speed limit on Three Mile Hill Road is 80 km/h.

We first proposed reducing the speed limit on this road to 60 km/h in our draft Speed Management Plan, which was open to public consultation in 2023.

We are consulting again following the introduction of the Government's Land Transport Rule: Setting of Speed Limits 2024, which changed the process for setting speed limits.

About this road

Three Mile Hill Road is an important secondary route between Mosgiel and central Dunedin. Three Mile Hill Road is identified as a high crash risk local road corridor, and crashes on this route can result in road closures and significant delays, reducing the reliability of this important connection. Improving safety on Three Mile Hill Road can help reduce disruption and support a more resilient transport network, especially for Mosgiel residents.

Reasons for reducing the speed limit:

Three Mile Hill Road

  • There is a significant crash history on the route, with 72 crashes recorded between 2020 and 2025. Fifty-two of these crashes occurred on the section for which we are proposing speed limit changes.
  • Three Mile Hill Road crosses steep terrain and features many twisting changes in alignment.
  • Traffic volumes on the route have increased by more than 50% since 2011, from approximately 3,700 vehicles per day to more than 5,600 vehicles per day in 2026.
  • The road serves a range of recreational, forestry, and industrial activities, creating frequent turning movements and interactions between different road users.
  • A lower speed limit would better reflect the road's alignment, traffic volumes and safety risk profile.

The proposal

Option 1 - Reduce the speed limit from 80 km/h to 60 km/h

Travel time impact: Approximately 13 seconds

The proposed change would reduce the speed limit from 80 km/h to 60 km/h on a 1.82 kilometre section of Three Mile Hill Road where the majority of crashes since 2020 have occurred.

The proposed speed limit would better reflect the road alignment  and safety risks, while improving safety outcomes for all road users.

Option 1 - Map

Three Mile Hill Road speed map - Proposed speed limit changes map

Option 2 - Status quo

No change to the current 80 km/h speed limit on the affected section.

Have your say

We want to hear your views. Submit your feedback before 5pm on Monday 30 November 2026.

Online feedback form

Requirements under the Rule

  • Cost benefit disclosure statement

    The Rule 2024 requires us to complete a cost benefit disclosure statement for the proposed speed limit changes. This sets out the expected impact of the speed limit changes on safety and travel times, and the expected implementation cost.

    RoadThree Mile Hill Road
    Distance1.82 km
    Existing Speed Limit80 km/h
    Proposed Speed Limit60 km/h
    Number of crashes in last 5 years52
    Estimated reduction in number of crashes each year0.2 serious injury crashes
    3.4 minor injury crashes
    6.8 non-injury crashes
    Current average operating speed68 km/h
    Decrease in expected mean vehicle operating speed 8 km/h
    Estimated impact on individual travel time13 seconds
    Estimated impact on collective travel times based on annual average daily traffic volumes4,885 hours
    Implementation cost$10,000
     

  • Role and function of the road

    Role and function of the road Three Mile Hill Road is an important transport corridor connecting Dunedin and Mosgiel, supporting the movement of people and goods between the city and the Taieri Plain.
    How it’s used Three Mile Hill Road is used by people travelling between Dunedin and Mosgiel and provides access to recreational areas, lookout points, forestry operations, industrial activities, and parking areas used by pedestrians and mountain bikers.
    Why a speed reduction has been proposed over other measures A speed reduction is proposed because it is a more practical and cost-effective safety improvement than major engineering works. The road's steep terrain, numerous curves, and constrained corridor make measures such as road widening or realignment difficult and expensive to deliver. Reducing the speed limit provides an opportunity to improve safety outcomes while better matching vehicle speeds to the road alignment.
    Alignment of proposal to the road safety aspects of the GPS A speed limit reduction on Three Mile Hill Road aligns with the safety objectives of the Government Policy Statement on land transport by supporting a safer transport system, reducing the likelihood and severity of crashes on a high-risk corridor, and encouraging travel speeds that are better matched to the road's geometry, traffic volumes, and operating conditions.

  • Data sources

    Existing speed limit NZTA National Speed Limit Register
    Proposed speed limit Based on road classification and consultation
    Number of crashes in the last five years NZTA Crash Analysis System
    Estimated reduction in the number of crashes each year Calculated using the NZTA Optional Cost Impact Analysis Tool
    Current average operating speed Megamaps
    Estimated average operating speed when new speed limit is in place Calculated using the NZTA Optional Cost Impact Analysis Tool
    Estimated impact on individual travel time Calculated using the NZTA Optional Cost Impact Analysis Tool
    Estimated impact on collective travel times Calculated using the NZTA Optional Cost Impact Analysis Tool

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