Final answer:
A vehicle on a two-lane road must yield the right-of-way to those on a four-lane road, following traffic laws that promote safety and efficiency.
Step-by-step explanation:
A vehicle driving on a two-lane road must yield the right-of-way to vehicles traveling on a four-lane road. This rule is part of standard traffic laws to ensure safety and the efficient flow of traffic at intersections where roads of different sizes and capacities intersect.
Drivers on the smaller road must wait for a safe opportunity to enter or cross the larger road. Situations mentioned, like the one involving Peter driving behind a slower vehicle on a four-lane road or the one with a car and truck approaching an intersection from different directions, highlight the importance of understanding and adhering to right-of-way rules to avoid accidents and ensure everyone's safety on the road.