Whether entering a city for the first time, or entering it for the five-thousandth, a traveler interacts with the environment to obtain cues. A first time traveler is very concerned about issues of navigation … where should I go? … how should I get there?, while the experienced resident may rely on memory and history to make those same decisions. Yet in complex cities, there are many places even the most experienced residents may never have explored, there are paths untaken, and like Heraclitus’ River, you never really step into the same city twice.

Much has been written about the human-computer interface, and there is research about user interface, and about ergonomics. These musings consider the interaction between the human and the city.
I am an experienced traveler. Not the most experienced, and certainly not the least. I have also lived and worked in five different metropolitan areas (Baltimore, Washington, Atlanta, San Francisco, Minneapolis) for at least five years each, and have passing familiarity with dozens of others.
Today when we travel to another city, we often do so by airplane. As a result, our first experience of a new city is that city’s airport, which, for better or worse, has a similar interface regardless of where you are. When departing a plane (and not making a transfer), first you look for signs for baggage claim and ground transportation. Airport signs are most often hung from the ceiling. They use a sans-serif font, often HELVETICA, and are easily read if one reads English (as do the readers of this piece). In many airports, second, third, even fourth and fifth languages may also be presented, based on the fluency of airport users, but to English-speakers, that other text is just noise to be ignored, or an quick and interesting way of learning bits of the local language (Niet Roken! is Dutch for No Smoking!).
The weary, English-reading traveler will follow the signs towards baggage claim, and walk (or stand on a moving sidewalk) covering a distance of sometimes more than 1 km, traversing an airport that was (generally) never designed to be this large, but grew and grew as demand once outstripped forecasts. In larger airports there are people movers or bus shuttles connecting some of the far points, often added as an afterthought, sometimes integrated into the design of a modernized or reconstructed terminal building or campus. If this is an international trip, there is a whole additional layer of immigration and customs that must be successfully navigated, with baggage claim after immigration and before customs.
Interfacing with the city includes areas that are somewhat understood, such as
Wayfinding , but it is much more, not simply how to find a path, but how to decide where to go, what to do, and when to do it.
We need to understand what happens once you leave the ubiquitous, ungainly airside of the airport and begin to see daylight (at least through the cracks of the double-decker roadway), and breathe fresh air (tainted ever so lovingly from the tailpipes of diesel engines). In airport terminology, this is the groundside. People who design airports are likely to have been fascinated with aviation as youth. I would venture almost no one goes into airport design to improve the groundside, the place where the city meets the world, or in the case of arrivals, where the world meets the city.
Once our weary traveler has collected his luggage, he seeks ground transportation. This is where difficulties begin. Unlike the relatively orderly air transportation system, where tickets are purchased in advance, signs are clearly marked, no one lets you on the plane with the wrong ticket. Ground transportation is often not thought through though. If you have arranged a package tour, or have someone to greet you at the airport, your problem is solved, you are not on your own, but have a handler who will take care of you. If you are on your own, you need to decide between taxi, limosine, shared-ride taxi, hotel shuttle, rental car, public transport. Unlike the inside of the airport, the signs here are quite chaotic. The ground transport lobby or the roadway just outside the airport are still a regulated form of capitalism in most US cities, but the regulation is much less. In some airports, agents do not merely standing behind counters, but rather go up to you and try to recruit you to their form of ground transport (which is undoubtedly more expensive than going market rates). The trade-off is the service they provide (first and foremost not having to continue to think about the decision, second, the vehicles are often higher quality, and third, it hopefully gets you to your destination faster). If you choose a rental car, hope that you made a reservation ahead of time, as walk-up fees are considerably higher. If you wish to take public transit, you will often have to catch another shuttle just to get to the public transport terminal, and then figure out which route you need.
And we have yet to leave the airport.
— dml