Pedestrian Algorithms

…17…16…15…

I’m not going to make it. I’m about 75 feet away from where the crosswalk begins, and it’s a boulevard. Plus my back is already damp from commuting with this backpack and shoulder bag. An 18-second trot will only make things worse.

I slow down, but eye the corner. I do have to go north: Should I make the turn? If I do, I run the risk getting caught at the the next light. What’s the right move? Let’s do the math.

If I wait it out here, I’ll be stuck at a newly green light staring at the “DON’T WALK” sign for the maximum possible duration. If I make the turn, there’s no guarantee that I won’t get stuck at the next light, but that’s no worse than what I’m facing now. And there’s a good chance I’ll arrive in the middle of the cycle somewhere and be spared the maximum delay. That would get me to the opposite vertex of my rectangle in less total time than if I stop and wait it out now.

I make the turn. And await the next opportunity to optimize my commute.