The chaos and destruction that might ensue during a tsunami evacuation in Napier is represented by a mass of red dots rushing around the city's streets.

Each dot is a person and they're all heading toward Napier Hill in a desperate bid to reach higher ground before the waves hit.

This is what a new computer model designed by GNS scientists looks like. It's been designed to save lives by modelling how people will likely evacuate and what can be done to improve or hasten their routes.

Produced for Napier, Lower Hutt and Christchurch, the modelling has been created by researchers and scientists from GNS Science, Massey University, East Coast LAB (Life at the Boundary) and the University of Canterbury. It will help planners who need to know where people are likely to flee to.

The modelling simulates the movement of people who have self-evacuated on foot and shows likely congestion areas during the daytime and at night and looks at options such as vertical evacuation. It uses household and population data to predict how long people will take to walk to their nearest designated safe point.

Japan and Chile, two other earthquake-prone countries, are doing similar modelling but the technology behind it is still being refined.

Project Leader of East Coast LAB (Life at the Boundary) ​Kate Boersen said the amount of congestion, road damage, liquefaction and fallen power lines etc following a strong earthquake would mean evacuating might not be as easy as some might think.

"That's why we say it's really important for people to practise their evacuation route, and that while they practise it that they consider what it would look like after an earthquake," she said.

The Napier modelling looks at the evacuations of the suburbs of Westshore, Ahuriri, Pandora, Napier South, Maraenui, Te Awa and Marewa.

Each person appears as a red dot. When they get to an area of congestion the dot turns purple.

"What we're finding is that there will be congestion in certain areas. For example people evacuating to Napier Hill will find the pathways congested and the hill will be dealing with an influx of a large number of evacuees," Boersen said.

Where areas of congestion are identified in the modelling recommendations will be made to the council and other agencies as to how routes might be improved.

Read the full article on stuff.co.nz here