The cellular view of a metro carriage
The tightest routine packing of humans anywhere, and the least social space on Earth.
The conditions of this room
Four numbers decide what a crowd does: how tightly it is packed, how loud it is, how fast alcohol arrives, and how much attention is available for the people beside you. Everything below is either a published figure or derived from one.
What those conditions do to people
Crush load is a real term in transit engineering: roughly four standing passengers per square metre, the density at which a carriage is considered full beyond comfort. It is the densest environment a person routinely enters, well past a nightclub and past most festival crowds.
It is also almost completely socially inert. The model records 1.27 encounters per person per hour and 74 lasting ties across 1,200 people over four hours, with a largest connected group of 24. Ninety percent of the carriage is in transit, and the available attention of the room is set at ten percent — eyes down, everyone already somewhere else.
A metro carriage and a queue are physically similar situations: strangers, stationary, side by side, for a long time. The difference is that a queue is waiting together for the same thing, and a carriage is a set of people whose journeys happen to overlap. That single distinction is worth an order of magnitude.
What the model produces
Measured output from a standard run: 1,200 people, 4 hours of venue time, fixed seed, no parameter overrides. Every room on this site is run under identical conditions, so these figures are a like-for-like comparison rather than a set of individually flattering runs.
The crowd is a simulation and is presented as one. What is not invented are its constants: walking speed against density, the proxemic zones, the collapse of speech range with noise, the Widmark blood-alcohol curve and the conversational group limit all come from published work, cited above and listed in full in the engine.
Real places like this
Every gathering below is modelled as this kind of room. Attendance figures are published numbers for the period stated.
Questions
What is crush load on a train?
Roughly four standing passengers per square metre — the density at which a carriage is considered loaded beyond comfortable capacity. Some networks record considerably higher during peak hours.
Why does nobody talk on the metro?
Density is not the barrier — a carriage is denser than a dancefloor. Attention is: almost everyone is mid-journey and mentally elsewhere, which in this model reduces availability to strangers by roughly a hundredfold.
Which is the busiest railway?
Shinjuku Station in Tokyo handles around 3.6 million passengers a day, the highest in the world; Mumbai's suburban railway carries around 7.5 million a day across its network.
How this is modelled
Each person is one cell with a position, a body mass, a Widmark distribution ratio, an openness trait and a reserve of energy. They walk at the speed the local density allows, drink at the rate the room serves, and when two of them stay within speech range long enough, a bond forms. Most bonds are nothing.
What separates an encounter that creates something from one that does not is whether it bridges two groups that were not previously connected. A tie inside an existing group mostly restates what that group already knows; a tie across a gap carries information neither side had. That distinction is Granovetter's, and it is the mechanic the whole model turns on.
One parameter has no citation and should be read as an assumption: attention, the share of a person available to whoever is beside them rather than to a stage, a road or a rite. It is the variable that separates a street crossing from a dancefloor at similar density, and it is the one this model asserts rather than borrows.