Interactive: Watch NZ leave alert level 4 for level 3 during Covid 19 lockdown

There's more traffic on our roads after New Zealand moved from alert level 4 to level 3, the latest data shows.

What will moving down the alert levels look like? Will life return to normal once the rules are relaxed? Using cell tower data provided by Data Ventures, we have built this interactive tool showing the daily movement of people across the country.

This data counts how many people are in a particular area in a given time using cell tower information. With this, we can tell how many people are in areas that are mostly offices, homes or shops.

The big peaks and troughs show people leaving the house to go to work and do their shopping during the day and going home in the evening. The red line shows the patterns of movement last week, and the broken grey line shows the week before last, and the full grey line is the same week from last year.

Over the next few weeks we will be updating this dashboard every Wednesday, so you can see how much each region is returning to normal patterns. Explore the data for yourself:

The data shows that retail areas in Auckland are busier than they were in alert level 4, but still barely halfway towards returning to normal levels. Meanwhile, more people have returned to offices, and people have maintained their lockdown patterns of going to parks and recreational areas during the day.

In contrast, Wellington - where many have been able to work from home - has seen little change from level 4. Only a very small proportion of people have gone back to work, and retail areas have also seen little change.

Where did the data come from?

The data provided to the Herald was collected by mobile service providers and is commercially sold by Data Ventures. The data is provided at a suburb (Statistical Area Unit 2) level for every hour of every day of the year, but only a total count is provided. This means that individual cellphone cannot be tracked with this data.

"This isn't the start of Big Brother," says Privacy Commissioner John Edwards.

"This is a tentative partnership between the telecommunications sector and the Government to really see whether a trusted agency like Statistics NZ can take this commercial data and turn it into something that's of value to the wider economy."