What you are looking at
Every dot on this map represents a road crash that was reported to New Zealand Police and entered into the Crash Analysis System, Waka Kotahi’s national record. The dataset runs from 2000 to the current year and contains a little over 900,000 crashes — about 8,300 of them fatal, 52,500 with serious injuries, and the balance ranging from minor injuries down to fender-benders with no reported harm.
At the national view, each district is shaded by how many crashes match your current filters. Zoom in and the choropleth gives way to individual crash points. Zoom in further and the points become clickable, with whatever the responding officer recorded — speed limit, weather, lighting, who was involved.
What the numbers mean and don’t mean
CAS is not a census of every crash in New Zealand. It is a record of every crash police were called to and recorded. Minor and non-injury crashes are systematically under-counted because many people just exchange details and move on. Fatal and serious-injury crashes are very close to complete because police always attend.
The location field is recorded to the nearest mapped feature — usually an intersection or a marked road point. A dot is rarely off by more than a few tens of metres, but it is not GPS-precise. Counts for the current year keep climbing as records work their way from the roadside into the central database.
The “per 100k” option normalises district counts against Stats NZ’s 2023 Census usually-resident population. It is the right comparison when you want to ask which districts have a road-safety problem relative to their size, rather than which districts simply contain more roads and more cars.
Things worth looking at
Set the year range to a single year and watch the choropleth shift between calendar years. The Far North, Westland and Wairoa districts tend to glow at any zoom because their crash rates per resident sit well above the urban averages — a long-running rural road safety story.
Switch the involvement filter to “Cyclist” or “Pedestrian”, zoom to your city, and the geography of vulnerable road users becomes obvious. Inner-city Auckland, Wellington and Christchurch dominate the cyclist counts not because they are dangerous in absolute terms but because they are where people cycle.
Set severity to fatal only, zoom to a stretch of highway you know, and the pattern over a decade often points at a single intersection or a particular bend. These are not random events.
If you have a story
The CAS data is open. Waka Kotahi publishes it under a Creative Commons licence and updates it monthly. If you spot a cluster on the map that doesn’t match what the agency or your council is saying about your area, that’s worth a phone call. Newswire reads what comes through this tool — if a pattern jumps out at you, drop a note in the comments and we’ll have a look.