As an urban commuter, every day is a treasure chest full of new and exciting surprises. One day, that surprise is that your bus came three minutes early, causing your left sandal to disintegrate entirely after you were forced to run uphill for two blocks. The next day, that surprise is that your bus never comes at all, and you miss an entire workday waiting for Godot, if Godot were a lurching, lumbering piece of mass transit.

“Life is chaos!” you say. “Life is unpredictable! Live, laugh, love!” You have just become a Chi Omega’s ankle tattoo.

But you are also correct. The reason that your commute is such a nonstop wonder-rollercoaster actually does have to do with chaos theory, which is a math thing and not the principle that rules your dating life. Researchers at the University of Ibagué in Colombia put together a model to try to explain why buses do the crazy things they do. From Pacific Standard:

Reader support helps sustain our work. Donate today to keep our climate news free. All donations DOUBLED!

Despite the model’s simplicity, fomenting chaos was easy. The key, the researchers found, is the minimum time it takes the bus to travel one block relative to the time it takes a red light to turn green. When those times are equal, the bus is synchronized with the lights, and it moves along smoothly.

Grist thanks its sponsors. Become one.

Something different happens when the red lasts a little longer, or if the bus moves a little faster. That, Villalobos writes in an email, throws the bus slightly out of sync with the traffic lights. “When you are getting near the light … you have to start braking, but before you stop the light goes to green and the [bus] starts accelerating again,” Villalobos explains. Do that “stop and go” over and over, he explains, and chaos ensues (i.e. your bus is late).

The study also suggests that aggressive driving is cause for chaos on the roads — huh! What a wild and crazy result.

Always remember: Life is like a box of chocolates, and also a Gwyneth Paltrow movie from 1998.

[youtube https://www.youtube.com/watch?v=j3xufuIJJxg]

Grist thanks its sponsors. Become one.