Stigmergy – Surviving In The Swarm

Ever watch a flock of birds fly in rapid formation, or a school of fish? If not, jump on YouTube; you’ll find plenty of examples. When you’re done with that, go watch a pro cycling peloton.

Notice something? Yep, cyclists swarm in the same fashion as birds and fish. Today we’re going to discuss swarm behavior, and how we can use it to our advantage.

Stigmergy is when the indirect coordination between individuals form self-organized, complex movements and structures without any planning or overall control from the individuals within. To quote Marsh & Onof from their 2007 paper on the subject, “It supports efficient collaboration between extremely simple agents, who lack any memory, intelligence or individual awareness of each other.”

If that isn’t a nice way to say “a bunch of cyclists,” I’m not sure what is.

A popular example of stigmeric behavior comes from ants. Ants exchange information by laying down a trail of pheromones for other ants to follow. Each ant lays down their own trail connecting from the food they’ve found back to the nest, creating a complex network of trails. This network becomes a shared external memory that the ants can use to retrieve food.

How does that apply to cyclists? Think about the last time you were in a large group of riders. Each rider tries to find the optimal path to the road. Each rider behind them tries to follow that path to stay in their wind shadow, or tries to improve on that path. So the riders toward the back of the peloton are being instructed where to go by the front of the peloton, without direct communication.

Cyclists self-organize to find the most efficient path. [Photo by Kristen Ryan]
Cyclists self-organize to find the most efficient path. [Photo by Kristen Ryan]
The front riders will set a pace, but when they pull off, the next set of riders will (usually, and hopefully, in many cases) follow that pace. This will propagate through the peloton as various riders take turns pulling. The more training the cyclists have, the less verbal communication is needed to optimize the movement of the peloton. Not to say that you shouldn’t talk anyway – PLEASE speak up when there’s dangers or you’re about to do something.

Now that we’ve got our basic, unordered-yet-organized structure, we add in some swarm behavior rules to maintain it:

  1. Move in the direction of your neighbors.
  2. Remain close to your neighbors.
  3. Avoid collisions with your neighbors.

When you’re in the peloton, you have the same goal as the other riders – get to the destination as quickly and efficiently as possible. That’s essentially rule #1 above: they’re going straight, you go straight. They start to turn, you start to turn. You follow the optimum line from point A to B to C, and so do they.

Everyone wants to go the same way, but everyone also wants to get there first. That means tight formations.

To remain efficient, you have to stay close to your neighbors (rule #2). This keeps you in the pocket of the air column created by the peloton, and keeps you as close to the optimum line of travel as possible (given a large number of other individuals trying to do the same thing). But, if you just follow rule #2 and someone makes a mistake, boom… you’re seeing stars and picking out a new bike frame.

We stay close enough to our neighbors to remain efficient, but far enough to remain safe – rule #3. When you put all three of these rules into effect, the whole peloton moves as a singular entity, reshaping itself to the course, travelling both quickly and efficiently, while remaining safe (well, most times).

So the big question is this: how do we use this controlled chaos to our advantage?

First, you have to be aware of your surroundings. You need to be able to feel the riders around you without seeing them. You need to hear them breathing, listen their their wheels, their pedal strokes. Hear when they coast and how they shift. It’s a lot to take in, because you’re not just doing this for one rider; you’re doing it with every rider that’s near you. The more you can understand the flow of the riders around you, the easier it will be to anticipate what they will do next.

Everyone wants to be near the front, but not ON the front. Photo Credit: Chris Wilcox, Eucha Classic Road Race Facebook Page

In a race, you can take advantage of these signals, movements, and behaviors to position yourself better. However, you have to keep in mind that other racers are trying to do the exact same thing. If you see a gap forming after a turn, you have to also think about who else around you may try to take advantage of that same gap.

If you can feel the movement, picture the overall flow, and anticipate it, you can also knowingly affect the structure and movement of the peloton. You can shift lines and close or create gaps. You can create disruptions in the flow (while hopefully not being dangerous about it), or you can smooth out disruptions by seeing and compensating for them. What’s interesting about this is that it doesn’t take much – you don’t have to be sporadic (in fact, don’t be; that’s when things get dangerous). A small, smooth shift from one side to another, a slightly wider angle on a turn, or a little more or less pedal pressure – that’s really all it takes. You just have to do it at the right time.

Minor variations of your movements can have a large effect on the entire system.

Unfortunately, this isn’t something you can just casually practice in a race. By then, you better know what you’re doing. So where can you practice? How about on every drive freeway or multi-lane road. The next time you drive somewhere, pay close attention to the cars around you. Shut the radio off, and just watch and feel. How do they behave when you speed up and slow down. If you move towards one edge of your lane or the other, what do they do?

Still use your blinkers (PLEASE!!!) but at the same time, try and adjust the behavior of the cars around your by small motions and acceleration/decelaration of your car, and see what happens. Do they let you in to switch lanes? Do they make that opening for you, or do they close it because their personality is aggressive? Feel the flow of traffic; get an understanding of how the things you do affect the movement of those around you. Moreover, learn to anticipate what others will do simply by how they’re behaving.