Why we must stop undervaluing the infrastructure that builds our future
Friday, 19 September 2025
Nick Leggett is chief executive of Infrastructure NZ
OPINION: The evidence is in, and it’s overwhelming. New Zealand’s newest highways and expressways are delivering benefits that far outweigh their lifetime costs.
Independent analysis (commissioned not by government but by local councils and industry) proves what many commuters, freight operators, and families already know in their bones ‒ these roads are transforming how our regions live, connect, grow and thrive.
The Transmission Gully and Kāpiti Expressway Economic and Social Benefits Report makes the case in black and white. In 2024 alone, Transmission Gully, Mackays to Peka Peka, and Peka Peka to Ōtaki delivered a combined $173 million of benefits to society.
That figure reflects measurable outcomes: faster and more reliable journeys, safer roads with dramatically fewer crashes, and broader accessibility for people and businesses.
Start with time savings. Transmission Gully alone saved motorists 1.9 million hours of travel in a single year, shaving an average of nine minutes off trips, and up to 31 minutes at peak times.
Mackays to Peka Peka cut travel times by an average of eight minutes, saving another 1.2 million hours annually. Peka Peka to Ōtaki chipped in with 700,000 hours saved.
Altogether, that’s 3.8 million hours returned to people’s lives every year. Time that can be spent working, with family, or enjoying leisure rather than being stuck in traffic.
Safety improvements are equally profound. On all three new routes, not a single death has been recorded since opening. Serious injury rates plummeted, with Transmission Gully’s rate falling from 0.6 per million vehicles on the old route to just 0.2 on the new one.
Across the three projects, the annual social cost of crashes has been slashed from $30m to $14.5m.
That’s a saving of $15.8m in human and economic terms every year ‒ fewer funerals, fewer families shattered, fewer businesses disrupted by road trauma.
Accessibility is another often-overlooked benefit. The new roads expanded the population catchment of Porirua’s CBD by 74,000 people ‒ a 15% increase. This means more workers, customers, and suppliers can reliably reach Porirua within an hour, strengthening its role as a regional hub.
House price gaps between Kāpiti, Horowhenua and Wellington City have narrowed by more than $63,000, evidence of stronger regional integration and rising confidence.
Businesses in eastern Porirua, newly connected by the Waitangirua and Whitby link roads, have already grown employment by 20% since 2014.
These benefits are not abstract. They show up in everyday life: in the mum or dad who can get home in time to read their kids a bedtime story, in the truck driver who completes an extra delivery run in a day, in the reduced sirens of emergency services responding to crashes.
They are the dividends of long-term investment in safe, resilient transport links. And yet, despite this mountain of proof, the national conversation continues to fixate on cost.
Transmission Gully’s price tag has been flogged in headlines for years, while its benefits ‒ now proven and immense ‒ rarely rate a mention. NZTA has struggled to tell the story, and successive governments have failed to champion the “why” behind these investments.
The result is a public debate distorted toward pessimism, rather than pride in what we have achieved and ambition for what comes next.
That brings us to the Ōtaki to Levin project, the critical next stage. Completing this link isn’t just about finishing a road. It’s about locking in the proven gains of safer, faster, more reliable journeys, and extending them into Horowhenua.
Every year of delay costs lives, time, and money. Every year of hesitation slows the potential of Levin to become a thriving, connected community.
Just as Transmission Gully has reshaped Porirua and Kāpiti, so too will the Ōtaki to Levin stage transform the opportunities of the lower North Island.
Let’s be clear: better design and greater efficiency in delivery are important. We should always strive to manage costs and improve execution. But we cannot lose sight of why we build infrastructure in the first place.
Roads like Transmission Gully are not vanity projects ‒ they are region-builders. They underpin growth, safety, and resilience for generations.
The benefits don’t expire when the ribbon is cut; they compound year after year, hopefully for centuries. Industry understands this. That’s why it stepped up to commission the benefits report when NZTA did not.
Local councils and Infrastructure New Zealand saw the need to quantify and communicate what our national agencies could not. It should not fall to industry to make the case, but until the government finds its voice, we cannot afford silence.
These projects are too important. Agencies should be completing these evaluations in line with Treasury requirements.
The lesson should be clear: instead of obsessing over short-term costs, it’s time to start valuing long-term benefits. We do not measure our schools or hospitals solely by their construction bill but by the lives they improve and communities they strengthen.
Roads ‒ and other transport projects like light rail ‒ deserve the same lens.
We need to see roads as more than asphalt. To see them as the backbone of regional prosperity and national resilience. To explain to New Zealanders not just what these projects cost, but what they deliver ‒ safer journeys, stronger communities, thriving regions.
And above all, to get on with finishing the job to Levin.