Final answer:
To safely return to your lane after passing another vehicle, wait until you can see the front of the passed vehicle in your rearview mirror, ensuring enough space to not disrupt its speed or safety.
Step-by-step explanation:
Appropriate Lane Change When Passing
When passing another vehicle, it's important to ensure that the maneuver is done safely. The right time to get back into your lane is when you can see the front of the vehicle you passed in your rearview mirror. This indicates that you have sufficiently overtaken the vehicle and there is enough space to return to your lane without causing the other driver to slow down or make an evasive maneuver to maintain a safe following distance.
In the scenario provided, Peter's impatience while driving in the city's business district demonstrates aggressive driving behaviors like tailgating and honking, which can be unsafe. Once Peter completes his passing maneuver, he should ensure he has enough clear space ahead of the elderly driver's vehicle before returning to his lane.