Updated March 28, 2020 16:21:44

Photo: People in cities worldwide have followed advice (and often rules) to stay home. (Unsplash, CC0)

This month, many of the world's busiest cities have ground to a halt amid coronavirus shutdowns.

Transport planning app Citymapper has released data indicating just how much our mobility has taken a hit in recent weeks.

The percentages shown in the chart are people's activity compared with the average level for that city, so you can see that at the beginning of March, some cities were even more active than usual.

What does it all mean?

As you can see, activity in Sydney and Melbourne nosedived to half of usual levels last week and again to a quarter of usual levels this week. By Wednesday, it had hit 20 per cent in both cities. This suggests the restrictions enacted by governments have affected behaviour.

Still, movement in Sydney and Melbourne is considerably higher than European cities in countries hit hard by coronavirus, which have fallen to single digits.

Activity in San Francisco has also been almost eliminated with a city-wide voluntary shutdown.

Singapore and Hong Kong are showing higher levels of activity. Both areas have flattened the curve when it comes to growth in new cases.

The Australian data comes as pre-publication modelling from the University of Sydney shows eight in 10 Australians must stay home to avoid an exponential rise in cases. If this slips to seven in 10, COVID-19 will continue to grow exponentially in Australia, according to the modelling.

Topics: infectious-diseases-other, respiratory-diseases, covid-19

First posted March 28, 2020 12:13:18