Final answer:
The maximum safe speed to travel at night when using low beam headlights is 40-45 mph. This is because low beam headlights have a limited range and higher speeds might reduce the driver's ability to stop in time or react to unexpected situations.
Step-by-step explanation:
The reason why 40-45 mph is considered the maximum safe speed to travel at night when using low beam headlights is because low beam headlights have a limited range. They typically illuminate the road ahead for about 160-250 feet. Traveling at higher speeds would reduce the driver's ability to stop in time if there are any obstacles on the road or if they need to react to unexpected situations.
At faster speeds, the driver might not have enough time to see and react to hazards on the road. Additionally, at higher speeds, the driver's field of vision might not be sufficient to identify potential dangers in a timely manner. So, driving at a speed of 40-45 mph allows the driver to have enough time to make decisions, react to situations, and stop the vehicle if necessary.
It's important to note that the speed limit and the conditions of the road should also be taken into consideration when driving at night.