If both sides of dividing streets were included from either direction there'd be fewer possible accidents, and no one would be breaking rules. Sometimes several riders are picked up early and ride around while others are being dropped off. If you're picked up 30 minutes early, you're likely not ready. Maybe some printed policies would help riders understand how their cooperation is needed. Often, drop-offs don't match the order you're picked up in.
Medical appointments come first.
Getting you there on time is very important to them. Then come grocery stops. The point could be made that every trip is important to the person taking it. But some priorities are necessary, and medical appointments are tops. The number of bags of groceries you can take is often not realistic.