Late-night food is concentrated in a small number of streets in any city, and those streets are consistent for decades. The pattern follows the places where crowds are released simultaneously rather than where people happen to live.
Demand arrives all at once or not at all
Trading through the night means most hours produce almost nothing, so the business depends on a brief window when a large number of people want food at the same moment.
Closing time at bars, the end of a performance and shift changes at hospitals or depots each produce that kind of simultaneous release.
A stall positioned on the path those crowds take can serve more people in an hour than it would in an entire quiet night elsewhere.
The menu is built for a specific customer state
Late-night food is eaten standing, walking or waiting for transport, so it has to be handheld, robust and finished without cutlery.
It also has to be produced in seconds from a holding state, since the whole crowd arrives together and will not wait through a cooking time.
This is why the format converges on griddled, fried and wrapped items across cities that otherwise share no culinary tradition at all.
Licensing hours draw the map
Where late trading is permitted is regulated, and the rules typically differ between areas of the same city and change with local policy.
Streets with clustered late licences develop the crowds, and the food follows the crowds rather than creating them.
Residential objections push those permissions toward commercial blocks, which is why late-night food streets tend to sit in areas where few people sleep.
Clustering protects the vendors
A single stall on an empty street looks risky to a customer at two in the morning, while several together look like a destination.
Concentration also means shared lighting, shared foot traffic and the informal safety of other people being present, which matters for a cash business at that hour.
Vendors compete with each other, but the cluster generates far more total demand than any of them would attract alone.
Transport nodes anchor the whole pattern
People leaving a night out converge on stations, ranks and bus stops, which makes those points the densest and most predictable crowds of the night.
Food positioned in the last hundred metres before that transport catches customers at the moment they are both hungry and stationary.
Change the transport, and the food moves within a season, which is the clearest evidence that the crowd rather than the street was ever the reason.