When we think of a major earthquake striking Aotearoa New Zealand, our minds first turn to collapsed buildings and the immediate toll on human lives.<\/p>\n
Few of us might ponder what happens in the days and weeks that follow, when supermarkets need restocking, fuel stations need replenishing and businesses need to keep goods moving around the country.<\/p>\n
One of the most critical links in the supply chain is the Cook Strait ferry network. It bridges State Highway 1<\/a> and New Zealand\u2019s main rail corridor, carrying more than 500 trucks a day and 5.5 million tonnes of freight each year.<\/p>\n Yet this system is reliant on just four roll-on, roll-off ferries operated by Interislander<\/a> and Bluebridge\u2019s StraitNZ<\/a>. Our newly published research<\/a> explored a disaster scenario in which Wellington and Picton\u2019s ferry terminals are put out of action for three months, along with several ports<\/a>, fuel facilities and parts of the road and rail networks.<\/p>\n Such disruption might simply appear an unavoidable consequence of the earthquake. But our findings suggest many of the biggest transport problems would stem not from the disaster itself, but from policy decisions made years earlier.<\/p>\n How NZ\u2019s freight network breaks down<\/p>\n Our scenario centres on a magnitude 8.5 earthquake and tsunami generated by the Hikurangi Subduction Zone<\/a> \u2013 New Zealand\u2019s largest and most active fault \u2013 which damages infrastructure across the lower North Island and upper South Island.<\/p>\n Scientists have calculated<\/a> a roughly one-in-four probability of such an event occurring within the next 50 years.<\/p>\n We found the ferry terminals present a vulnerability, with participants describing them as ageing infrastructure not built to modern resilience standards. If knocked out, freight operators would immediately need to find other ways of moving goods between the islands.<\/p>\n But the alternatives are far more limited than they first appear.<\/p>\n Although air freight could move urgent goods, such as medicines and high-value products, it is expensive, has limited capacity and already faces shortages<\/a> of pilots, engineers and specialised ground staff.<\/p>\n That would leave coastal shipping carrying much of the burden. Yet it too has limited spare capacity.<\/p>\n There are not enough vessels, containers, refrigerated equipment and trained personnel to suddenly accommodate a large increase in demand. That challenge has been compounded by the recent closure of Pacifica\u2019s domestic service<\/a>.<\/p>\n The remaining ports would also come under pressure. Vessels and containers would be redirected to a smaller number of available locations, while existing labour shortages would make it difficult to expand capacity quickly. Trucks collecting and delivering freight would add further congestion.<\/p>\n Road networks<\/a> would face similar pressures. Alternative routes would be longer, creating delays and increasing demand for trucks and drivers, worsening existing workforce shortages. Many roads would also carry more heavy vehicles than they were designed for, increasing wear and tear and maintenance needs.<\/p>\n The disruption would extend well beyond transport itself. Fuel pumps depend on electricity. Truck drivers rely on electronic payment systems to fill up. Freight operators need telecommunications to coordinate deliveries and share information. <\/p>\n If these systems failed after a disaster, the disruption would quickly cascade through the freight network.<\/p>\n Can NZ avert a disaster after a disaster?<\/p>\n While the earthquake is what exposes many of these vulnerabilities, they often are not what creates them.<\/p>\n Take ports. Congestion on the country\u2019s docks after a disaster may seem inevitable. But it would also reflect years of under-investment or lengthy approval processes that limit spare capacity.<\/p>\n The country\u2019s largest port, Tauranga, has spent years seeking resource consent<\/a> to expand its berths, leaving it less able to absorb sudden surges in freight demand if other ports become unavailable.<\/p>\n The same pattern can be seen elsewhere. A shortage of coastal shipping vessels can come back to uncertainty over marine fuel policy and limited support for the sector, discouraging investment in new ships.<\/p>\n Difficulties finding enough truck drivers, port workers, or shipping and aviation personnel similarly reflect workforce shortages that existed long before the earthquake.<\/p>\n Overall, we identified 43 constraints linked by 99 cause-and-effect relationships. But they ultimately traced back to just 18 root causes spanning six broad areas of government policy.<\/p>\n This suggests freight resilience is not only about how quickly infrastructure can be repaired after a disaster. It also depends on the policy settings already in place.<\/p>\n That means investing over the long term in critical infrastructure<\/a>, coastal shipping<\/a>, transport network redundancy and workforce development, while ensuring timely resource consent processes for infrastructure expansion.<\/p>\n