Boston Logan: Arriving Or Departing?

This morning while catching an early flight to Seattle, I was reminded of one of the things that always confuses me about Logan Airport: the road signs. I mention this from time to time to friends and colleagues, but get only blank stares, making me realize the issue must be entirely my own. But after years of a mental block that makes me incapable of understanding the logic, I just need to get this off my chest.

Shortly after entering Logan Airport, the road forks with the right fork labeled "Departures", and the left fork labeled "Arrivals". So if it's 5 AM and you are driving to Logan to depart on a flight to Seattle that leaves from Terminal A, which one do you choose? It's obviously a trick question since choosing "Departures" will bring you to the upper level of Terminal A where cabs and buses drop off passengers, and "Arrivals" will bring you to the lower level of Terminal A, where cabs and buses pick up passengers. The right answer is: neither. Instead you need to follow the signs for "Central Parking", park, then walk over to Terminal A.

Just as you wouldn't assign three possible values to a boolean, Logan shouldn't try to impart three possible choices in two signs. What about this crazy idea: Dropoff, Pickup and Park.