Final answer:
In heavy traffic, drivers turning left must yield to oncoming traffic and pedestrians to maintain safety and efficient traffic flow. Traffic signals play a vital role in regulating vehicle speed and ensuring safe pedestrian crossing, particularly in high traffic areas.
Step-by-step explanation:
When making a left turn in heavy traffic, you should always yield to oncoming traffic and pedestrians. The rules of the road necessitate that drivers give right-of-way to ensure safety and to manage the flow of traffic efficiently. Especially as vehicles often speed through the intersection without regard to the posted speed limit, yielding is crucial to prevent accidents. Additionally, the presence of a traffic signal has a significant impact on traffic behavior. Since it requires vehicles to stop, it inherently slows down traffic, preventing them from speeding through. This also enhances pedestrian safety, as the signal provides designated times for individuals to cross intersections safely, which is particularly important around areas with high foot traffic like school and college campuses.
Furthermore, while rules such as stopping at a red traffic light are fundamental, there can be exceptional circumstances where breaking such a rule could be considered due to the potential for greater utility or necessity, as highlighted by the hypothetical situation involving a pregnant woman needing to reach a hospital. However, this is an exceptional case and should not be taken as a general rule for traffic behavior.