Which of the following conditions may cause you to reduce your speed according to the Basic Speed Law?

The Basic Speed Law in California requires drivers to operate their vehicles at a safe and prudent speed based on the current conditions. This means that you must adjust your speed to ensure safety for yourself and others on the road.

When considering heavy traffic, it is essential to recognize that a significant number of vehicles can create a dense and potentially hazardous environment. Reducing your speed helps maintain safe distances between vehicles, allowing for better reaction times and minimizing the risk of collisions.

Adverse weather conditions, such as rain, fog, or snow, can significantly impact road conditions, visibility, and vehicle handling. Slowing down in these situations is critical because it allows for safer navigation, helping drivers react quickly to unexpected obstacles or changes in traffic patterns.

The recognition that both heavy traffic and adverse weather conditions can necessitate a reduction in speed illustrates the comprehensive nature of the Basic Speed Law. It emphasizes the importance of evaluating the driving environment and adjusting one's speed accordingly to promote safety. Therefore, the choice indicating "all of the above" accurately encompasses both scenarios where reducing speed is warranted.