Flood warnings are a type of risk communication that alerts the public of potential floods. Flood warnings can be communicated through mobile devices and should convey enough information to keep the user safe during a flood situation. However, the amount of detail included in the warning, such as the depth of the flood, may vary. The purpose of this study was to: (a) extend our prior research on flood warnings by recreating the written driving scenarios into the driving simulator; (b) deepen the understanding of human decision-making in risky situations; and (c) investigate how to best inform drivers of floods by design to keep them protected. We examined the effects of flood warning information on the actions taken by drivers in various driving scenarios in a driving simulator. Participants were tasked to drive to a restaurant after receiving instructions and a type of flood information warning during each scenario (flood, no flood, flood of 6 inches, flood of 6 inches maximum). Their actions taken, trust in the navigation system, understanding of the situation and scenario, and perceived risk were measured for each type of flood information warning. We found that participants accepted the alternate route more when in a scenario with a flood present compared to the no-flood scenario. The level of detail of the warning did not influence the actions taken. These results deepened the understanding of human decision-making and can guide future flood warning designs to keep drivers protected from flooded roadways