People tend to delay preparations to defend themselves or confirm the need to leave before a bushfire until they can observe the blaze directly, research into three major fires has found.

In addition, the work by the Bushfire and Natural Hazards CRC and commissioned by the NSW Rural Fire Service found greater reliance on mobile phone warnings. With carriers offering differing coverage, however, residents were getting uneven service of those alerts.

The blazes studied included the Sir Ivan fire that began during a day of catastrophic fire danger rating last February. It burned more than 55,000 hectares and destroyed 35 houses, a church and other buildings. A coronial inquest into the event was announced this week.

Farmers race the front of a fast grassfire ahead of the huge Sir Ivan fire near Cassilis. Credit:Nick Moir

The other two events examined were the Currandooley fire, 40 kilometres north-west of Canberra and the Carwoola fire 20 kilometres south east of Canberra. Both burned more than 3000 hectares, and began on days of severe fire danger in January and February 2017, respectively.