This arrangement comes with the added expense and inconvenience of an intermediary transportation mode between the highway vehicles and the aircraft. If that mode is a heavy rail, such as a short subway, it works best if its track is linear, hence the comb or marina-like pattern. Such airports require huge land area and are often found far from the metropolitan core. Chicago, O' Hare International Airport. Acceleration is associated with areas and energy and defines the spatial parameters of the moving vehicles and their travel domain.
Uncertainty is overcome by proper dissemination of information about departure gates and times.
For informational purposes it is best to have a high concentration of people in the center of the terminal. The terminal is the space where this sorting occurs. Capacity of structures, number of runways, departure gates, luggage carousels, storage, announcements, open ticket counters can all be smaller, fewer, and have less capacity by making the passengers, surface vehicles and aircraft wait in lines . Because the aircraft and surface vehicles have such different passenger capacities, and because of favored times of day for departures, holding areas, waiting rooms and long lines are an inevitable part of the travel effort to move from one travel domain to another. The terminal building is the permeable membrane or interface that facilitates the exchange between surface vehicles and aircraft.