What should drivers do during times when lighted lamps are not required?

When lighted lamps are not required, it is important for drivers to ensure visibility and safety in other ways. Carrying two red flags is a proactive measure to signal their presence and alert other drivers to their location, especially in low-visibility conditions such as fog, heavy rain, or at night when they are required to have lights turned off. This approach can help prevent accidents by making it clear to others that there is a vehicle present.

The other choices do not provide the same visibility enhancements that carrying red flags offers. While driving slowly and checking mirrors frequently can improve safety, they do not directly increase visibility to other vehicles. Turning on hazard lights is typically meant for when a vehicle is stopped or experiencing problems, rather than as a standard visibility measure when lamps are not required. Hence, having two red flags is the most effective solution among the options when lighted lamps are not in use.