Before revision: 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) .
After revision: In general, people underestimate the time that could be saved when increasing from a relatively low speed - e.g., or - and overestimate the time that could be saved when increasing from a relatively high speed - e.g., or .