Final answer:
A motorist exiting a private road or driveway must yield to vehicles on the main road, as part of traffic laws for safety. This pertains even if the motorist is encountering a slow-moving vehicle driven by an elderly person, as in the scenario provided.
Step-by-step explanation:
A motorist coming from a private road or driveway must yield to all vehicles traveling on the main road. When exiting a driveway or a private road, it is crucial for the driver to yield to oncoming traffic to avoid collisions and ensure road safety. This rule falls under traffic laws which are designed to maintain order and safety on roads.
In the given scenario, if Peter were coming out of a driveway onto the business district road, he would need to wait and let all other vehicles, including the slow-moving car driven by the elder person, pass before entering the lane. Traffic regulations are imperative, regardless of a driver's age or the speed at which they prefer to travel. Ignoring these rules can lead to fines, endangerment of all road users, and in severe cases, legal consequences.