Final answer:
An operator must not exceed the speed that is reasonable and prudent under existing circumstances, considering conditions and adhering to the law while prioritizing safety.
Step-by-step explanation:
According to the Transportation Code, an operator may not drive at a speed greater than is reasonable and prudent under the circumstances existing. This means that even if the speed limit is 35 miles per hour, drivers like Peter must always consider the current conditions, traffic, weather, and visibility to determine a safe driving speed. Being stuck behind a car going the minimum speed or having an emergency, such as the pregnant woman scenario, may still require adherence to traffic laws unless exceptional circumstances justify otherwise. In the context of the scenarios provided, it's important to weigh the de jure speed limit (the legally established limit) against the de facto speed limit (the speed at which law enforcement is likely to take action), always with a view to the safety of oneself and others.