Andrew Kelly / Reuters

Underground: Safer Than the Surface?

Aaron Chalfin , Alex Chohlas-Wood and Morgan Williams Jr.

October 02, 2024

How trains and platforms compare to the street 

How trains and platforms compare to the street 

Over the last two years, both the press and local government have paid a great deal of attention to crime on the subway. The New York Post alone has published dozens of articles on serious public safety incidents in the subway, and Mayor Eric Adams has commented at length about subway crime at countless “in-person media availabilities” and town halls. Public pressure has influenced policy in real and costly ways, including a surge of 1,000 National Guard and state police officers in the subway and Adams’ pilot evaluations of security technology at select stations, not to mention hundreds of millions of dollars spent on police overtime costs.

While each public safety incident — especially the most serious — deserves attention, the City’s budget is limited, and the NYPD’s staffing levels are at their lowest level since 1990. So any intervention in the subway necessitates removing scarce resources away from other critical service areas, like regular street patrols. 

The City and state’s reallocation of staff and money to address subway crime prompts the question: Is this the best use of precious resources? In other words, is it better to focus limited resources on the subway instead of other important public spaces, like the city’s streets? This question seems especially relevant given that many serious crimes, like assaults, have been rising citywide over the last few years. 

We wanted to tackle this question by looking at the data and asking: Are the subways actually unsafe relative to the other ways that New Yorkers spend time outside of their homes? Statistically speaking, is it safer to spend an hour on the subway system or on a city street? You’d think it’d be easy to get the answer, but it’s not.

While it is relatively easy to count the number of crimes and classify where they happened, it is difficult to know how much time individuals spent on the city’s subways and streets last year. Even when subway crimes involving known victims are reported to the NYPD, the point in one’s commute that these offenses took place may be unclear. We do know how many subway rides were taken, but we don’t know how long each ride took — not to mention how much time people spent waiting on platforms or walking through tunnels and stations. By the same token, we don’t know how much time was spent outside on city streets. However, by making some educated guesses about how people spend their time, we can say something about what is most likely to be true. 

The share of public violence that occurs on the subway is small, a fact which implies that people would have to spend a very small proportion of their time in public on the subway for it to be more dangerous. 

We begin by comparing how many crimes happen on the subway as opposed to in other public spaces in the city, like streets, parks and alleyways. (We focus on violent index crimes, which include murders, rapes, robberies and serious assaults, as these types of crimes tend to be reported to law enforcement and thus well measured in the data.) In 2019, there were 935 reported violent index crimes on the city’s subway system and 12,967 reported violent index crimes on city streets. Overall, 6.7% of the violent index crimes that occurred in public happened on the subway. In 2023, the number of violent index crimes on the subways had risen to 1,120. The share of public violent index crimes occurring on the subways had fallen to 6.5%. 

This comparison highlights two important realities that are worth internalizing. First, while crimes are up on the subway since the prepandemic period, they are up even more in other public spaces — calling into question whether there is anything unique about the subway, or if the subway is simply experiencing the same dynamics that are faced by all public spaces in the city. Second, the share of public violence that occurs on the subway is small, a fact which implies that people would have to spend a very small proportion of their time in public on the subway for it to be more dangerous. 

 Benchmarking subway crime 

Are New Yorkers, in fact, less safe on the subway than they are in other public spaces in New York City? Given the limits of available data and the enormous variation in risks that New Yorkers face depending on how frequently and at what times they use the subway, this is a difficult question to answer definitively. But we have enough information to engage in some informed speculation.

Let’s say we are interested in computing the number of violent index crimes per person per hour on the subway versus city streets. The number of crimes is simple enough to calculate. The NYPD was aware of 1,120 violent index crimes committed on the city’s subway system in 2023 and another 16,079 violent index crimes that occurred on a city street or in another public place like a park or parking lot in 2023. 

The number of person-hours spent in each of these venues requires some speculation, but we will keep our speculation rooted in facts and reasonable assumptions. First, consider the amount of time subway riders spent on the train. In 2023, straphangers took over 1.3 billion subway rides (accounting for fare evasion using estimates published by the MTA). Let’s say that the average ride took 30 minutes, in addition to another 10 minutes spent waiting on the platform and traversing tunnels and stairs. That is about 880 million person-hours spent in the city’s subway system in 2023. On a person-hour basis, that works out to almost 1.3 violent index crimes per million person-hours spent in the subway system.

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Next, let’s consider the amount of time that was spent on the city’s streets. This is even more difficult to calculate, given the paucity of data on exactly how people spend their time in the city — and we’re talking here about residents as well as commuters and tourists. Instead of engaging in a fool’s errand and trying to estimate these fundamentally unknowable quantities, we instead ask a slightly different but equally revealing question: How many person-hours would have to be spent on city streets to make last year’s risk on the surface equal to our estimate of the risk faced on the subways? To calculate this “breakeven point,” all that is required is a bit of simple algebra. We’ve done the math for you, and it’s over 12.5 billion hours. 

Is it likely that people spent at least 12.5 billion hours on New York City’s streets in 2023? It sounds like a big number, but New York is a big city. So let’s think about what this means in more interpretable terms. Approximately 8.3 million people lived in New York in 2023, and including a daily increase of over a million commuters and tourists, a reasonable estimate is that about 9.5 million people spend time in New York City each day. Spread across 9.5 million people, 12.5 billion person-hours annually works out to over 25 hours spent outside per person per week. That is, if the average New Yorker in 2023 spent more than 25 hours per week on city streets, the subways would have posed a higher hourly risk for serious violent crimes than city streets.

What do we make of this breakeven number? Is 25 hours a lot or a little? In our view, the true average is likely to be lower than this. Consider a typical New Yorker who works in the office five days per week, socializes occasionally and spends time outdoors on the weekends. Between walking to and from the subway and waiting for buses, our New Yorker might spend an hour every weekday outside during their commute. Consider another five hours per week for errands like going grocery shopping and picking up lunch, an estimate that we think is, if anything, on the high side given that we’re only talking about the time that someone is on the street. Finally, consider a long walk in Central Park on a nice day and some time with friends over the weekend for another eight hours outdoors. This estimate adds up to 18 hours in a given week. But our breakeven point requires New Yorkers to average seven more hours outside every week, across the entire year — even on the coldest and snowiest winter weeks, and on the hottest or rainiest days.

While proof is ultimately beyond our grasp, this calculation suggests that the subways are unlikely to be especially dangerous compared to other public spaces in New York City. They might even be a little safer. 

But what does this calculation miss? First, we need to underscore: It does not establish a causal relationship between spending time on the subway (or on the street) and changes in the risk of being a victim of violent crime in any given hour. Our analysis is simply an accounting exercise that shows us where the risk of crime was likely to be greatest last year. But if some people last year spent much more time on the subway than the street, they could still expect an hour on the subway to be a bit safer than an hour on the street — at least on average. 

Second, these overall averages do not rule out that specific New Yorkers may be less safe on the subway than they are on the streets. For certain, there are some New Yorkers who face more risk on the subway than outside. Consider a janitor who only rides the subway late at night, including weekend nights, but most of their time on the street or in parks is spent playing soccer with friends in Flushing Meadows Park. For this resident, it’s probably true that riding the subway is a riskier activity per hour than their time on the street or in a park. Still, the data suggest that, on average, the subways are likely to be safer than other public spaces in the city. 

Subways are unlikely to be especially dangerous compared to other public spaces in New York City. They might even be a little safer.

Even if it’s true that riding the subway is safer than being on the street, what’s the right decision for the NYPD or the City when deciding where to put cops on patrol? It’s possible that a little overstaffing — relative to crime risk — is justified underground, due to the unique setting of riding the subway. People are a captive audience. When crimes happen on a train, it may be hard to escape. Many people have few available alternatives to using the subways to get around. Perhaps it’s crucial to make people feel particularly safe on the subway, given that transit likely serves as an economic engine for the city. And incidents on the subway may be particularly salient for perceptions of crime, given that the subway is a familiar space that so many New Yorkers inhabit on a frequent basis. According to this view, it might be rational for policymakers to prioritize enforcement on the subway.

On the other hand, the increased attention paid to crimes when they happen on the subway could potentially compromise public safety elsewhere in the city. Given the attendant resource constraints, City leaders should think carefully about the opportunity cost of moving police officers off their regular beats to spend more time underground. Such a reallocation is not without logic, but the expected benefits need to be weighed against the potential costs — a consideration that is especially important in light of the calculations in this piece.