City Population, Street Traffic, and Daily Passage

A modern city can produce several very different numbers that all sound relevant to shishim ribo: residential population, the number of people on the streets at a given time, entries by commuters and visitors, daily vehicle or passenger traffic, and the number passing a single point. Halachically, those figures are not interchangeable.

Before using any number, one must know what the underlying definition is counting.

Population is not the same as passage

A census asks who lives in a defined area. A traffic count asks how many movements occur along a route. A commuter estimate asks how many people enter from elsewhere. A count of people currently in public streets asks something different again.

One person can also generate many traffic movements in a single day. A commuter may cross several counters, travel in a vehicle with other passengers, and return along the same route. A raw traffic total therefore need not equal a number of unique people.

The classical sources did not use modern census and transportation categories. The useful question is which modern statistic most closely corresponds to the people or movement that a particular Posek says to count.

Rashi includes people who enter the city

Rashi's formulation in Eruvin 59a concerns a city into which six hundred thousand people did not regularly enter. The Ritva explains that, according to Rashi, the six hundred thousand do not have to be settled residents. Large cities can satisfy the idea through the people who regularly enter for commerce and similar purposes.

In modern language, that makes the residential census alone incomplete. Regular commuters and other entrants may matter even though their permanent homes are outside the city.

It would still be imprecise to replace Rashi's words with a modern statistical category and say that he “counts commuters.” His term is broader: people who regularly enter the city. A commuter is an obvious modern example of such an entrant, but the halachic category is defined by the source, not by the terminology of a census agency.

Rav Moshe rejects a separate 600,000 count for every city street

Rav Moshe Feinstein addresses the modern city question directly in Igros Moshe, Orach Chaim I:139. After reviewing the language of Rashi and other sources, he writes:

ולכן אני אומר שודאי סגי בזה שישנם בעיר ולכל היותר שישנם ברחובות כל העיר ס' רבוא

“Therefore I say that it certainly suffices that they are in the city, and at most that six hundred thousand be in the streets of the entire city.”

His comparison is to the Midbar. The six hundred thousand were found throughout a large encampment. They were not all required to pass through every individual path of the camp. Rav Moshe therefore says one cannot derive a rule that every street in a city must itself carry six hundred thousand.

This changes the unit of measurement. Under that approach, one does not stand at a single intersection and ask whether the entire 600,000 crossed there. The streets of the city are considered together.

But Rav Moshe treats an independent road differently

The city-wide rule does not make individual traffic irrelevant. In the same responsum, Rav Moshe distinguishes a city from derachim, roads outside the city. A road has no larger city-wide public population to combine with it. If the shishim ribo requirement is being applied to such a road, the six hundred thousand must pass along that road.

In Orach Chaim IV:87, Rav Moshe states the distinction even more explicitly:

בדרכים צריך שיעברו ששים רבוא בכל יום ... אבל בעיר הוא רה"ר בזה שישנם בעיר ששים רבוא

“On roads, six hundred thousand must pass every day ... but in a city it is a reshus harabim by virtue of six hundred thousand being in the city.”

He then adds the reverse case. If a particular road has six hundred thousand passing along it, that road itself is a reshus harabim even if the city does not contain six hundred thousand.

Thus Rav Moshe recognizes two routes to the numerical condition. A city can be judged by its aggregate public presence, and a heavily used road can be judged by its own passage.

City-wide population and the census total

A frequent shortcut is to summarize Rav Moshe as counting the population of the whole city. His actual later formulation is more exact.

In Orach Chaim IV:87 he says there is room to be lenient and require that six hundred thousand be found throughout the streets of the city during the times when people ordinarily go out for their needs. Each individual street can have far fewer. The question is the aggregate public presence across the city streets.

He then discusses how one estimates that public presence. A dense city may have a very large residential population while only a portion is outdoors at one time. Rav Moshe therefore speaks in terms of an umdana, an estimate of how many residents would be found in the streets. His discussion of the Midbar is part of that estimate.

This is not identical to saying that every resident listed by a census automatically counts at all hours of the day.

People entering from other cities count

Rav Moshe expressly addresses cities with substantial incoming movement:

ובעיר שיש בה הרבה נכנסין צריך להתחשב גם עם אלו הנכנסים מערים אחרות דאם איכא הס' ריבוא בצירוף הנכנסים ממקומות אחרים נמי הוא רה"ר

“In a city into which many enter, those entering from other cities must also be taken into account. If there are six hundred thousand by combining [the city] with those entering from other places, it is also a reshus harabim.”

This is the clearest basis for including the modern phenomenon of commuters and visitors in a Rav Moshe calculation. The source does not require that the six hundred thousand all sleep within the city limits. People who enter from elsewhere can join the count.

The same passage also clarifies a question Rav Moshe had left open in Orach Chaim I:139. In the earlier responsum he had considered whether people inside their homes might count as part of the city's six hundred thousand. In Orach Chaim IV:87 he writes that it is more plausible to include only those hanimtza'im bachutzos, those found outside in the streets and public areas.

For Rav Moshe, therefore, the relevant modern question is closer to public presence than to a bare population figure.

Vehicles are part of modern public movement

The classical descriptions naturally speak of people walking. Modern cities move enormous numbers of people by cars, buses, trains, and other vehicles. Rav Moshe does not treat vehicular movement as halachically invisible. In Orach Chaim V:28, discussing modern public streets, he writes that movement by automobiles also produces this public use: ve'af hahiluch al yedei hamechoniyos osin zeh.

That statement establishes that people moving by vehicle cannot simply be excluded because they are not pedestrians. It does not, by itself, supply a complete traffic-engineering protocol. The responsum does not specify, for example, whether a transportation count should use vehicles, passengers, unique persons, entries, or repeated journeys as the statistical unit.

Those details matter whenever modern traffic datasets are used. A vehicle count is not automatically a people count.

Rabbi Levin uses a more residential city model

Rabbi Sholom Dovber Levin also rejects the proposition that all six hundred thousand must physically traverse one individual street. His 2022 formulation is:

אלא שיהיו ס' ריבוא גרים שם ומשתמשים ברחובות

“six hundred thousand live there and use the streets.”

This is more residentially framed than Rav Moshe's later public-presence model. Rabbi Levin argues that the city contains the requisite population and that its streets serve those residents. The fact that all six hundred thousand do not cross the same street does not remove the city's reshus harabim status under his reading.

His position is built from his reading of the Alter Rebbe and the Rebbe, so the complete source analysis belongs on The Alter Rebbe and the Requirement of Shishim Ribo. It should not be blended anonymously into Rav Moshe's formulation. The two approaches overlap in rejecting a separate 600,000 count on every city street, but they are not identical in how they describe the people who form the count.

Four statistics that should not be confused

For a modern city, it is useful to keep four numbers separate:

Figure	What it measures	Where it may matter
Residential population	People whose residence is within the defined city or area	Rabbi Levin's resident-city formulation; an input to Rav Moshe's estimate
Incoming commuters and visitors	People entering from outside	Rashi's language of regular entrants; Rav Moshe's explicit inclusion of entrants
Aggregate public presence	People actually found throughout the city's streets and public areas	Rav Moshe's later city-wide formulation
Passage on a particular road	Movement through the route itself	Rav Moshe's independent-road rule; the literal local-passage reading

A fifth figure, vehicle volume, can be evidence of movement but must be converted cautiously if the halachic question concerns people. One car is not necessarily one person, and one person can pass several counting points.

“Every day” is itself disputed in meaning

The Shulchan Aruch says “six hundred thousand pass through it every day.” Yet the Mishnah Berurah notes that he could not find the condition of every day in the Rishonim who require shishim ribo. Their language instead speaks of six hundred thousand being commonly found there.

That makes the daily period important but not self-explanatory. A numerical claim such as “this street has fewer than 600,000 users per day” answers only a particular reading. It does not establish what Rashi meant by people regularly entering a city, what Rav Moshe meant by city-wide public presence, or what Rabbi Levin means by six hundred thousand residents using the city's streets.

Applying these categories to New York and Crown Heights

The halachic definitions come first. The factual application comes second.

For New York and Brooklyn, the relevant factual work includes the geographical unit being counted, resident population, people entering from outside, movement through public streets, and the difference between passenger counts and vehicle counts. Those figures also have dates and boundaries that must match the halachic proposition being tested.

The verified New York and Brooklyn figures are therefore treated separately on New York and Brooklyn: Population, Commuters, and Visitors. The purpose of the present page is to make clear what each number can prove before it is used.