Every month, more councils across New Zealand are asking the same question:

“Should we use rubber roundabouts on our next project — or are we better off going straight to concrete?”

It’s a fair question. With budgets tightening and LCLR (Low Cost Low Risk) funding no longer available, temporary infrastructure like compact rubber roundabouts has become a hot topic. They promise faster installs, lower TTM costs, and flexibility. But how well do they hold up in the real world?

To help answer that, we sat down with Ian Martin, a senior transport engineer from Dunedin City Council (DCC). His team has installed around 15 compact roundabouts across the city, including three trial rubber ones, and he gave us a transparent breakdown of what worked, what didn’t, and where they’d use them again.

By the end of this article, you’ll have a clear understanding of where rubber roundabouts work well, where they don’t, and how to decide whether they’re the right fit for your next project.

How Dunedin’s rubber roundabout trials were implemented

Dunedin starts with trial designs first to save money, test layouts, and get community feedback.

Dunedin City Council’s approach to improving intersection safety is often to use temporary roundabouts before progressing to more permanent designs. This saves money, enables monitoring, and gets the community on board.

In 2023, three trial sites used Vanguard’s rubber roundabouts. This allowed the council to experiment with layouts and measure community acceptance before committing to full installations.

 Images: Three trial rubber roundabouts installed on Dunedin’s road network

Where rubber roundabouts work well

Rubber roundabouts perform best for trials, temporary fixes, and quiet residential streets.

The increase in the number of roundabouts and the reduction in their size has given DCC multiple examples of intersections where serious crashes have reduced and traffic speeds have dropped. That’s a huge win for reducing risk by improving safety.

Council has found that rubber roundabouts work best when used as:

• Temporary trials to evaluate intersection layouts.
• Short-term solutions for known trouble spots.
• Permanent options on low-volume, low-heavy vehicle residential streets.

Trial roundabouts are also useful for network monitoring:

“We have one intersection in Mornington where we are sure that traffic takes an alternative route to avoid a difficult right turn. If a roundabout was installed, it’s likely to dramatically change the route chosen by most drivers and alter at least two nearby intersections.” – Ian Martin

A trial roundabout allows monitoring to show how the change impacts driver route choices on the surrounding network, potentially saving money by reducing the priority of upgrading nearby intersections.

Where rubber roundabouts might let you down

Rubber roundabouts struggle under heavy traffic, have limited reuse, and require smooth road surfaces.

The main challenges Dunedin encountered using rubber roundabouts include:

• High cost relative to fixed budgets
• Durability under heavy traffic, including damage after 1.5 years on a road with 10,000 vehicles/day and 10% heavy vehicles (see image)
• Inability to reuse the modules if damaged
• Installation problems on uneven surfaces.

“The road needs to be of a good enough quality to support the fixing method”. – Ian Martin

Rubber roundabouts are not suitable as a permanent installation along bus routes or main arterials with high heavy vehicle volumes. The roundabout is likely to suffer damage. But, using the rubber roundabout in a shorter trial (1.5 years) allowed DCC to collect data about layout and performance and determine that the right choice for a permanent structure at this location would be concrete.

Image: Rubber roundabout damaged by high volume heavy vehicles after 1.5 years

Is rubber cheaper? What Dunedin found about cost

Rubber can offer TTM cost savings, but concrete may be more cost-effective long term for heavy traffic sites.

Let’s take a look at approximate installation costs and pros and cons of rubber and concrete roundabouts.

Price range comparison

“When we install permanent concrete roundabouts (permanent), the overall benefits are greater than temporary/trial rubber roundabouts. These include improved pedestrian desire lines (particularly for those using mobility aids) and the ability to realign the kerb. However, the cost of concrete/permanent roundabouts is significantly higher, making a direct price comparison less reasonable.” – Ian Martin

So there is no obvious winner. It all depends on the site and purpose. If there is a concrete truck on-site, realigning kerbs, concrete is probably the most economical. If not, then rubber is the cheaper option.

Temporary/trial vs permanent: Where do rubber roundabouts work best?

Rubber roundabouts work well for trials and low-volume streets, but durability drops in heavy traffic areas.

Flexibility is probably the main consideration of using rubber roundabouts, especially for trial sites and short-term solutions to a problem intersection that may be replaced as part of a much larger project.

When rubber works well

• Residential streets
• Trial sites for community consultation
• Low traffic volumes (less than 10% heavy vehicles).

When rubber struggles

• Heavy traffic routes
• Sites requiring vehicle overruns (bus or freight routes)
• Poor surface conditions.

Real-world lifespan expectations

• 5–10 years on quiet residential streets
• 1–2 years on high-volume routes with heavy vehicles.

“Temporary is becoming mid to long-term (5-10 years) as funding becomes tight. When it works, temporary infrastructure is soon adopted as the norm by the general public.” – Ian Martin

Factors to consider when choosing between concrete and rubber

Site selection, traffic conditions, budget, and consultation needs should guide your choice.

Dunedin City Council recommends evaluating:

• Ease of consultation
• Potential trial benefits
• Size of the roundabout
• Percentage of heavy traffic at the site
• Cost comparison
• Available funding.

“Cost remains the biggest barrier. We have no shortage of sites. Our constraint is what we can afford. The cheapest option will usually win out.” – Ian Martin

With budget constraints and no LCLR funding, DCC is considering using rubber roundabouts in low-volume, residential areas as a longer-term solution.

How community consultation shapes council projects

Community buy-in can make or break a roundabout project, so trials with removal options are valuable.

“Trials have proven to involve a fairly straightforward consultation process and allowed us to demonstrate that a lot of the potential negatives people perceive aren’t factually based.” – Ian Martin

Community buy-in is essential. Without early engagement or consultation, a recent proposal for a mini roundabout at a three-way intersection was scrapped after local opposition over cost and perceived lack of need. In this case, a trial using a rubber roundabout would have generated more trust with residents and allowed for feedback.

The benefit of rubber? It offers councils an option to trial designs with a promise of removal if feedback is negative or it doesn’t work.

Final insights for councils considering rubber roundabouts

Rubber roundabouts are an effective tool for trials and temporary improvements on low-volume streets.

Rubber roundabouts are not a universal solution, but they are a valuable tool to help council engineers:

• Speed up delivery
• Minimise TTM disruption
• Test designs before committing to permanent upgrades
• Solve local intersection safety issues, especially on low-volume residential streets.

If you’re planning an intersection upgrade, your next step is to read our detailed article “Compact Roundabouts: A Straightforward Way To Make Your Community Safer”, which includes independent research and additional council experiences to help guide your decision.

Need advice for your next intersection project?

Our team has worked with councils across New Zealand to design practical, cost-effective intersection upgrades using both trial and permanent solutions.

Contact us today to talk through your site requirements, get honest advice, and see if rubber roundabouts could be a good fit for your network.