On those rare days when I drive to work rather than take the bus, I’m compelled by my basic sense of thrift to park in a cheap lot on the corner of River Street and Beretania, even though our offices are at Bishop and King. That leaves me with the classic pedestrian’s dilemma: What’s the most efficient way to traverse Chinatown on foot?

This involves a more complicated calculus than you might imagine. In fact, my 10-block walk from the parking lot to work offers a choice between at least 44 different routes (11 Diamond Head blocks times four makai blocks). These range from a simple dogleg route along Beretania and Bishop (or, conversely, River and King), to more than a dozen complex zigzag routes that negotiate as many as seven turns. Amazingly, though, all these routes cover essentially the same distance. So, how to choose? A few months ago, I wrote here about my “5 Ethical Rules for Pedestrians”. Today, I’ll share with you the “4 Principles of Pedestrian Logic.”

1. Make the Pythagorean Theorem work for you: Remember, the shortest distance between two points is a straight line. So, while the city might appear to offer a series of right-angle turns to choose from, the careful navigator always has his eye out for the diagonal. If you can walk through a block instead of around it, that’s almost always the faster route. That’s why the occasional hypotenuse, like Tamarind Park or Pioneer Plaza or Union Square, is so valuable for the pedestrian; it’s the only way to actually shorten the distance you have to walk. But even a straightaway offers the occasional hypotenuse. A sidewalk, for example, is a rectangle, not a line; if you follow the long diagonal from street corner to building corner, you’ll shave a few yards off your trek. Also, it may be cheating, but diagonals also pass through some buildings. Major buildings like the Pacific Davies Center, the First Hawaiian building and Harbor Court all have front and back entrances. So do many Chinatown markets. And if you’re walking from the Capitol to Aloha Tower, remember: the square root of the Iolani Palace grounds is always less than the sum of the square roots of Richard Street and King.

2. Maintain continuous motion in the right direction: Pedestrian efficiency can be measured in time as well as distance. Put briefly, waiting idly at an intersection is a waste of time if it’s possible to continue moving toward your destination. On any diagonally route through the city, it frequently makes no difference whether you turn or go straight when you reach an intersection. If that’s the case, keep moving. Turn later if you have to, but don’t waste time standing still. (Unless that’s the point of your little walk.) Consider my morning walk from the parking lot to work. As long as I stay within the box formed by River, King, Bishop and Beretania, and as long as I only move Diamond Head and makai, no turn is a mistake. If I’m walking along Beretania and reach a red light at Maunakea, there’s no reason to stop. Turning makai on Maunakea is just as direct as going straight on Beretania, but much more efficient, since I don’t have to wait for the light to change. Choosing to move over standing sometimes simply means walking on the other side of the street, so long as crossing the street means your still going in the right direction.

3. But always preserve your options: Still, any diagonal route through the city consists of a finite distance north/south and east/west. If you use up all of one or the other, you may lose the option of staying in continuous motion. To use my morning Chinatown walk as an example again, if I simply go Diamond Head on Beretania and turn right on Bishop, I have no options left if the traffic light changes at Hotel Street. All I can do is wait. On the other hand, the closer I stay to the imaginary diagonal that runs from the parking lot to Bishop and King, the more options I’ll have at each intersection. I can turn; I can cross the street; or, if the light is about to change, I can continue straight. So, all other things being equal, the smart pedestrian always turns toward the diagonal.

4. The person farthest from the destination steers: Of course, you don’t always walk alone. So, who navigates when you have a companion? (In a crowd, no one’s ever in charge.) Now that you’re versed in pedestrian logic, you may think you should lead, but that will take some strategizing. Here’s a ploy you can use to help keep you and your friend on the straight and narrow. As you stroll along, try to stay on the side farthest from your destination. That way, when you reach each decision point along the way, if you subtly turn toward your hypotenuse to preserve your options and maintain continuous motion, you’ll impinge ever so slightly on the personal space of your companion. Usually, that’s all that’s necessary to induce the appropriate change in their direction. If not, though, it’s probably just politic to let them lead. You could, of course, just politely say, “This way is better.” But that would probably require a long explanation of principles of pedestrian logic. And now one loves a know-it-all.

Screenshot: Google Maps