Collision Avoidance

The Social Choreography of Walking

In 1966, sociologist Lyn Lofland noted how films and TV shows often depict the naive “country boy” struggling to walk through a city crowd. It suggests that navigating urban pedestrian life is a learned social skill; one that operates without formal instruction or clearly articulated rules. And yet, learned or not, remarkably, city dwellers manage to weave past each other on busy pavements with very few collisions.

What makes this so striking is that most of us couldn’t explain how we do it.

There’s no pedestrian highway code, no formal choreography, and yet people seem to coordinate their movements instinctively. This seamless, often unconscious coordination is the product of an intricate blend of psychological, social, and environmental factors—a silent, everyday dance we perform with strangers.

Streaming and the Flow of Foot Traffic

One of the clearest patterns in pedestrian dynamics is streaming—the spontaneous formation of directional lanes. In many Western cultures, people tend to veer to the right; in countries like Australia and New Zealand, the left; tendencies that reflect local norms rather than innate behaviours.

Streaming is adaptive: it flexes to the density of the crowd, the width of the pavement, the pace of walkers, and the presence of obstacles.

In tightly packed settings, people often fall into step behind one another, minimising friction and making efficient use of limited space. When someone wants to move faster, they typically break from the stream, sometimes even stepping into the road where these unwritten conventions are absent.

Monitoring, Body Gloss, and the Unspoken Signals of Movement

At the heart of this coordination lies a process of monitoring. Pedestrians scan their environment visually, often unconsciously, to detect movement trajectories. Sociologist Erving Goffman called attention to body gloss; the subtle bodily cues that reveal a person’s likely direction or intentions.

A shift in posture, shoulder angle, or even a flick of the eyes can provide information about a person’s intended path.

John Kaufman observed that walkers scan a long, narrow visual field extending forward. They read shoulders like signposts, track heads and faces for cues, and may even use someone walking towards them (the approaching person's gaze direction) as a kind of human rear-view mirror. These micro-observations, usually below the threshold of awareness, enable people to anticipate and adapt in real time.

From Streaming to Stutter-Steps: The Dance of Avoidance

When two people end up on a collision course — streaming breaks down, or paths cross unexpectedly — more overt coordination kicks in. Goffman described gestural prefigurement: small, anticipatory motions that signal which way a person intends to go. If the other party picks up on it, this can trigger what he called the checked body check; a reciprocal readjustment where both parties align their movements.

Sometimes, of course, both people move in the same direction to avoid each other, leading to the familiar pedestrian ‘dance’ — a moment of mutual hesitation and correction. Eye contact can help, but it’s not essential. A 2022 study published in Scientific Reports showed that mutual anticipation, not mutual gaze, is the key.

Walkers mainly rely on body cues—not eyes—to predict others' paths.

Types of Overlap: Partial and Total

The nature of the encounter also shapes the avoidance strategy. With partial overlap — say, one person’s right shoulder overlapping the other’s — both tend to pass in the way that requires the least effort. But total overlap, where paths fully converge, requires more active coordination. Here, conventions (like passing on the right) or gestural communication may come into play.

When conventions are strong and shared, communication is minimal. But when norms are unclear — due to cultural differences, crowd density, or situational confusion — people rely more heavily on subtle signals. Mistimed movements or unclear cues can lead to collisions or awkward near-misses, requiring quick, adaptive responses.

Gender, Posture, and Social Norms

Avoidance strategies are also shaped by social and cultural norms, including gendered expectations. Wolff (1973) observed that men often make open passes, walking with an upright, unconstrained posture. Women, by contrast, are more likely to make closed passes, angling their arms protectively across the chest — a gesture that may reflect cultural norms.

Distraction and Disruption: When the Dance Falters

The choreography breaks down when attention lapses. Research from the University of Tokyo and UBC highlights the disruptive effects of smartphone use: even a few people texting while walking can disturb the flow of an entire crowd. These ‘distracted walkers’ fail to provide clear body cues, reducing predictability and increasing the risk of collision.

Such individuals show reduced situational awareness, make fewer path adjustments, and affect not just their own safety but that of those around them. The dance, it seems, depends on being present and aware.

Groups, Bonds, and Social Formations

Crowd behaviour also shifts when people walk in groups. Friends, families, or couples often form V-shaped or side-by-side formations to facilitate communication. These groups move as cohesive units, taking up more space and requiring solo walkers to adapt around them.

Interestingly, the strength of social bonds affects how others respond. Pedestrians are more likely to avoid intruding on tightly knit groups, making wider detours to preserve the group’s integrity. This reflects not just spatial considerations, but social awareness.

The Subtle Art of Walking Together

All these behaviours—from streaming and monitoring to gestural communication and group dynamics—demonstrate how walking in public spaces is anything but random. It's a subtle, sophisticated choreography built on a mix of learned conventions, instinctive responses, and real-time adaptation.

Despite the apparent chaos of a busy street, collisions are rare. That’s because human beings, even when distracted or rushed, are remarkably adept at reading one another. We anticipate, adjust, and adapt—often without a word.

Conclusion

The seemingly simple act of walking through a crowd is a complex social performance. It depends on unconscious monitoring, shared norms, expressive gestures, and real-time adaptation. When the system works, it’s invisible. But its elegance lies in that very invisibility.

The next time you glide through a busy high street without so much as brushing a shoulder, take a moment to appreciate the unspoken coordination at play. This is social life in motion — a dance we all perform, without a script.

References

Collet, P. (1974). Social Rules and Social Behaviour. Oxford.

Feliciani, C., et al. (2021). People Who Text While Walking Actually Do Ruin Everything. Wired.

Goffman, E. (1972). Relations in Public.

Gregorj, A., et al. (2023). Social aspects of collision avoidance. arXiv.

Kaufman, J. (Unpublished observations cited in Collett, 1974).

Lofland, L. (1966). In the Presence of Strangers.

Murakami, H., et al. (2022). Spontaneous behavioral coordination between avoiding pedestrians requires mutual anticipation rather than mutual gaze. Scientific Reports.

Sayed, T., et al. (2024). Texting while walking puts pedestrians in danger. UBC News.

Moussaïd, M., et al. (2010). The walking behaviour of pedestrian social groups and its impact on crowd dynamics. arXiv.

von Sivers, I., & Köster, G. (2014). Dynamic Stride Length Adaptation. arXiv.