Assessing motorist behavior during flash floods in Tucson, Arizona

Weather events often force motorists to drive in unsafe conditions or alter travel plans. Both decisions are imbued with costs that drivers may minimize by developing adaptation behaviors that facilitate safe travel. This study examines motorist behavior in Tucson, where urban flash floods are potentially avoided by strategies such as changing the route or trip timing. A sample of 108 residents completed a stated adaptation questionnaire regarding which behaviors they take to avoid floods prior to departure and upon encountering a flood. A multiple regression analysis tests whether behaviors depend on demographic characteristics, familiarity with flood locations, and previous experience entering floodwaters. This study also considers the types of information that people seek upon encountering a flood. The results highlight the importance of flexibility and familiarity for motorists’ decision making. Fewer adaptation behaviors are used for urgent commute trips, but route switching is common for the most frequent trips to work, school, and home. Pre-trip behaviors account for most differences because most respondents use adaptation behaviors upon flood encounter, but age, ethnicity, and previous experience with floods are key factors. Differences in flood avoidance behaviors appear to be linked to travel flexibility, not just propensity to take risks. These results also highlight the significant potential for communicating alternate routes to help motorists reduce flood exposure and other point-location hazards while minimizing travel disruption.