Transportation engineers are studying how drivers make route choices with real-time traffic information. They want to improve models that predict how drivers pick the best route. The researchers found that drivers don't always choose the most efficient route based on expected travel time. By testing drivers in a simulated environment with different traffic scenarios, they discovered that drivers consider both average travel times and the variability of travel times when making decisions. This study will help refine transportation models to better reflect how people actually choose routes.