What is especially important when choosing the speed for driving along tree-lined avenues with narrow roadways?

Your answer combines two important considerations for driving along tree-lined avenues with narrow roadways.

First, estimating the lateral distance to both the trees and oncoming traffic is crucial because it helps maintain a safe distance from obstacles that could pose a risk of collision. This reflects the principle of maintaining a safe distance, which is emphasized in German traffic regulations to prevent accidents.

Second, the possibility of needing to stop within half the visible distance when a wide vehicle approaches is also key. This highlights the importance of being prepared for unexpected situations, especially in narrow lanes where visibility may be limited, aligning with the rule to adapt speed to conditions.

Together, these aspects ensure that drivers remain vigilant and prepared for changes in their surroundings, which is essential for safe driving in such environments. Missing the third option about rapidly changing light conditions could lead to underestimating the difficulty in gauging distances under varying light, which is an important factor for safety. Therefore, a complete understanding and application of all relevant considerations is vital for safe navigation.