The time-saving bias describes people’s tendency to incorrectly estimate the time that could be saved (or lost) when increasing (or decreasing) speed. In general, people underestimate the time that could be saved when increasing from a relatively low speed (e.g., 25 mph or 40 km/h) and overestimate the time that could be saved when increasing from a relatively high speed (e.g., 55 mph or 90 km/h). People also underestimate the time that could be lost when decreasing from a low speed and overestimate the time that could be lost when decreasing from a high speed.