How many seconds should a driver follow behind a motorcycle going less than 40 miles per hour?

When following behind a motorcycle traveling at less than 40 miles per hour, a driver should ideally maintain a following distance of at least 2 seconds. This distance allows for sufficient reaction time and space to react to the motorcycle's movements, which can be different from that of larger vehicles due to their size and maneuverability.

Maintaining a 1-second gap can be overly aggressive and does not provide enough time for the driver to respond in case the motorcycle makes a sudden stop or swerve, particularly since motorcycles can stop more quickly than cars. A greater following distance, like 3 or 4 seconds, may be more appropriate for higher speeds or in adverse conditions but is not necessary for speeds below 40 miles per hour. Thus, the correct answer emphasizes the importance of safety and appropriate reaction time when following a motorcycle.