Flood-related fatalities have been an ongoing problem in Australia since the early 1900s. Deaths during floods rank second only to heat waves in natural disaster fatalities. Approximately 159 people died from flooding in Australia during the last 15 years, with half (53%) due to driving through floodwater. NSW, together with QLD, represent 74% of flood fatalities. Rural and regional areas in NSW are especially at-risk.
Driving through flood water is a pressing issue, and has been a persistent problem behaviour that has been tough to shift.
The following reflects how the Behavioural Insights Unit (BIU) worked through this behavioural issue, and brainstormed problems, during a recent masterclass with NSW State Emergency Service (NSW SES).
Identify behavioural barriers or triggers
There are behavioural biases acting as barriers to the desired behaviour of avoiding the flood water. Drivers who venture through flood water seem to overestimate their ability to survive and underestimate the risk, displaying an optimism bias. Research by Julia Becker and colleagues suggests that this is even more the case if drivers are very familiar with the environment. This same familiarity with the environment and a particular road could also mean that the status quo bias is at work. Deviating from the usual route taken regularly, such as their route home, would require more effort and planning than sticking with the tried and tested.
Drivers may also consider themselves atypical, using the representativeness heuristic. They might think: “only old ladies or inexperienced youngsters get stuck”. Yet research shows the biggest flood fatalities in Australia are men (up to 80%). One of the most devastating floods in NSW in recent times occurred at the Shoalhaven, just over half (53%) of the people who drove into flood water were men, 38% were women, while the rest were unknown (9%).
Based on their expertise, NSW SES discussed how the emotional decision-making was an especially strong pull. It’s not just about driving to a time-pressed situation or the desire to get home, but rather why individuals might feel compelled to continue to reach their destination. If people have children waiting for them, or cattle that need tending, or some other priority they feel strongly depends on them, they will drive through floodwater to fulfil their commitment.
In Figure 1, the BIU modified the work of Irving Janis and Leon Mann to look at critical decisions faced in emergencies.

From this decision pathway, the following reflections by the driver could be possible:
- The first question a driver may ask could be “Is there a serious risk if I do nothing?” To this the answer could be “Yes my kids won’t be fetched from school”.
- This would lead to the next consideration of whether there is a serious risk if action is taken. “Yes I could get stuck”.
- This would bring on the question on whether more information would help: “yes it would help to know my kids are safe and it would help to know if it’s safe to cross”.
- To answer these questions would require time and the driver may decide that there is insufficient time to research and deliberate, and so make a bad decision, venturing into the floodwater.
Each of these decision points offers potential for a behavioural insights solution.
To see how these questions were workshopped, how solutions were developed for behavioural change, and how you can apply this to your work, head to the BIU website.