What is it that keeps walking from improving its market share in the field of ways for people to move to where they should have been in the first place? One factor is walking's vulnerability to rain, and another is unreliable air conditioning, and there's also how only eight percent of the population can play a compact disc without carrying extra equipment. But the biggest drag must be the risk of collisions.
People walking are subject to all sorts of collisions, mostly from other walkers. This makes them slightly lose their balance, or realize they didn't actually want to go wherever they were going, or suffer tragedy as loose body components fly off and burst into flame. This must be the problem. I'm running out of other reasons not to walk places.
My solution comes from the car industry, so don't tell them: a set of signal lights for pedetrians to warn others what they're going to do. This way others can react and, if necessary, file injunctions. The lights could be set on a pedestrian's shoulders, or on the belt, if the pedestrian has no shoulders, or on the ankles, if the pedestrian has no shoulders or belt. If the pedestrian has no ankles either I don't know what to do. It's a new technology. Some details will have to be worked out.
A pedestrian who means to start turning left will signal a left turn, indicated by the light on their left shoulder or other body part, unless they can't remember left from right. This suggests a subsidiary market in peel-on skin decals for left and right; I offer this franchise to anyone who wants it. It will be left in an cardboard box by the front porch next to the pot of flowers of a type I could only identify if I knew anything about flowers. On the other hand, a pedestrian meaning to turn right will signal with their other left light.
A pedestrian holding on both left and right lights is either coming to a halt or starting mitosis. Either way you'll be glad not to step into this. Life is difficult enough without getting someone else's cytoplasm all over you. A pedestrian already stopped, who signals with both lights, and who has already divided into two or more genetically identical daughter selves, may be assumed to be getting ready to move again, so offer your spare cardboard boxes and packing tape.
Several short taps on the light on the same side indicate a desire to spin, left indicating counterclockwise (as viewed from above), right indicating clockwise (as above), unless I have that the wrong way around. Matters are reversed in the other hemisphere, or when on the sidewalk between the pedestrian's companion and the curb.
A short and then long tap on either light indicates that the corresponding arm is about to be put out. Why, I don't know. Maybe they want to use hand signals in addition to the lights, so it's only fair to warn people on the side. The important thing is being considerate.
A quick tap on the left and then the right lights indicates the pedestrian is in a giddy mood and is about to skip. Provide some space and perhaps grin as you remember times in your life when you felt like skipping. You might hum something cheerful in encouragement. A quick right and then left, on the other hand, means a standing high jump, and no particular path needs to be cleared except by those directly above the pedestrian.
If both lights are tapped for a long pulse, then a short flash, then a long pulse and another short flash, followed by two long, one short, and one long flashes, and then one long and two short flashes, then the pedestrian is in distress and is a skilled telegraph operator from the British Empire between 1904 and 1912. Render assistance as appropriate.
If we don't find some resolution to the people-bumping-into-each-other problem I figure walking will come to an end as a way of life in a few thousand years on the outside. Slightly longer, indoors or under tents.
Trivia: The landing site, Crater Alphonsus, for the Ranger 9 lunar probe, which was launchd 21 March 1964, was not selected until after the 10th of March. Source: Luanr Impact: A History of Project Ranger, R Cargill Hall. NASA SP-4210.
Currently Reading: Great Fortune: The Epic of Rockefeller Center, Daniel Okrent.
(Posted, I believe, before midnight universal time.)