Mitch Resnick

Mitch Resnick appears briefly as the designer of a traffic simulation that demonstrates how minor variations among individuals can disrupt coordination. Using StarLogo, he modeled cars whose movements initially produced smooth traffic but began to generate jams when their speeds and positions varied and they reacted to one another. The example gives concrete form to the book’s distinction between the benefits of diversity in decision-making and the difficulties diversity can create when people must coordinate.

The Traffic Simulation

Resnick’s simulation was devised with StarLogo, a computer program used to model how interactions among individuals can produce results no individual intends. As described in his book Turtles, Termites, and Traffic Jams, traffic flowed smoothly when cars departed at evenly spaced intervals and traveled at equal speeds. The orderly outcome depended on those regular conditions: each vehicle moved without having to adjust to a fluctuating stream of neighbors.

The pattern changed once car speeds became variable and vehicles had to respond to one another by braking or accelerating. Traffic jams appeared, and only a small amount of randomness in each car’s position and speed was needed to start the disruption. The simulation thus made congestion legible not as the decision of a single driver, but as an emergent consequence of many local reactions.

Diversity and Coordination

The example complicates the claim that diversity is always an advantage. Different perspectives and judgments can improve decision-making, but variation among drivers can make a shared course of action harder to sustain. On a road, each driver must anticipate what others will do; individual responses to changing speed can amplify rather than absorb disruption.

Resnick’s model also sets up a question about whether greater uniformity could solve the coordination problem. A radar trap, by forcing drivers to slow quickly and making their speeds more variable, could itself create a traffic jam. The issue is therefore not simply whether drivers are diverse, but how variation and reactions to it interact within a system where each participant has only a partial view.

Significance in the Argument

Resnick’s simulation connects individual-level behavior to collective outcomes: smooth flow can give way to disorder without any single participant intending to cause it. Its force lies in the contrast between regular movement under uniform conditions and congestion once cars begin adjusting to one another. In the book’s wider discussion, the example cautions that a quality useful for good judgment—diversity—may complicate coordination when people’s actions are interdependent.