NYC's Worst Ultra Marathon

Tue, 28 Oct 2025 08:00:00 +0000

The NYC Toilet Challenge: A 579-Mile Marathon Nobody Asked For

Did you not make it into the NYC marathon this year? I have an alternative for you…

If you have the right mixture of ambition and questionable GI state, then here is a route that connects all of NYC’s public restrooms for you:

In total it is a mere ~579 miles as the crow flies. At 100 calories per mile, that is 57,900 calories required, or about 165 Beef Chalupa Supremes.

This was generated using NYC’s open dataset on public restrooms. Since solving the shortest path is tantamount to the traveling salesman problem, this is an approximation using nearest neighbors with some pre-computed clusters (and special handling for Staten Island, because, well, Staten Island is special…). The route looks reminicent of the listeria adhesion protein shape that is probably very active in anyone’s belly that attempts this.

Tighten your laces, eat that questionable leftover food from last night on your counter, and I will see you out there.

1066 Public Bathrooms for 8 Million People: A dive into NYC's Restrooms

Fri, 24 Oct 2025 08:00:00 +0000

Got to go? NYC has about 1066 public restrooms that might be of use to you. Thanks to pretty meticulous record keeping we can get some insight into how well the restrooms service the city. Let’s dive in!

Overall

1066 restrooms sounds like a lot, but in fact it is pretty low for a city the size of NYC. Looking at the 100 biggest cities in the US, NYC is ranked 93rd in terms of restroom availability with 16 restrooms per 100,000 people (St. Paul is ranked first, with 210 restrooms per 100,000). There are some efforts to improve this, in particular a recent push to nearly double the number of bathrooms by 2035, however that is going to be hampered by the high cost of building or renovating, and then maintaining, a bathroom in NYC - some analysis puts it at $3.6M to build a restroom, and at 1000 additional restrooms needed to double, something has to change on a cost front.

Here they are scattered around the city:

There are some great resources for digging further on the geographic distribution of bathrooms, in particular:

got2gonyc.com - Theodora (“Teddy”) Siegel’s great map of restrooms
nyrestroom.com - originally started in a Uber driver forum

In general, the restrooms that we have are fairly well equipped - 62% of them have changing stations and 58% of them are fully accessible.

Public restrooms are operated by several city agencies, including the transportation authority, libraries, and parks. The parks service maintains the majority of them (728/1066). In 1997 the NYC parks service started keeping records on the cleanliness of public restrooms through the parks inspection program, which can give us some insight into how clean these facilities are. Park restrooms are inspected on average twice per year, and are graded for overall quality and some details like the amount of litter, graffiti, and structural issues. Let’s get into some questions you might have about NYC’s potties!

How clean are our restrooms?

Not bad according to the data - of course, we should all manage our expectations when we walk into a public facility. Conditions appear to have been steadily improving, with recent numbers showing that only ~15% of facilities are in unacceptable condition. That data has a “dirty bump” in 2020, likely due to the realities of NYC during the pandemic. The dominating features that lead to unacceptable conditions are litter and missing soap (16% of the cases each), though missing toilet paper is a common problem (7% of the cases).

Are men or women messier?

An ancient question that the restroom inspection data can give us some insight into… turns out men’s and women’s restrooms are fairly equal in terms of conditions, with men’s rooms slightly (but consistently) edging out women’s rooms in terms of grime. About 15% of men’s rooms are categorized as unacceptable, versus 13.6% of women’s rooms.

Does restroom cleanliness correlate with wealthy areas?

I had a (pessimistic) hypothesis when I started this analysis that I would find a relationship between facility cleanliness and the wealth of neighborhoods. After all, the nicest public bathroom in NYC is located in a high end neighborhood (Bryant Park), and its renovation and upkeep is funded by a private coalition. That seems like an outlier though; the correlation between median income and restroom quality is directionally aligned, but weak at only 7%. That points to a fairly equitable maintenance program.

Are restrooms evenly distributed in the city?

Looks like it - controlling for population and excluding hot spots like highly visited public parks, restrooms density loosely matches population density.

Parting Thoughts

The public restrooms in NYC seem to be fairly distributed and managed well, but there is not enough of them, and it is not clear from the data that there is an easy answer for that. We need to build more restrooms everywhere in the city to get us closer to top-tier cities higher in the rankings.

NYC Parks are Getting Cleaner

Fri, 03 Oct 2025 08:00:00 +0000

You are lying on a blanket in the park, soaking up the rays, watching kids run around, and you reach over to find… broken glass? If you have been in the city long enough you have had an experience like this. Our parks are usually beautiful communal spaces, but it is impossible for them to escape the tradedy of the commons - good news though, since 2017 NYC has been collecting inspection records of how clean our public space are, and things are getting better!

Records indicate that since 2022, we have observed a 34% decrease in “filth” in our parks (and yes, the level of inspections appears constant at around 3,000 per year). The inspection data includes flags for the presence of five issues - animal waste, broken glass, illegal dumping, graffiti, and medical waste. Each of them have gone down in the past 3 years:

Category	% Decrease
Animal Waste	29%
Broken Glass	31%
Illegal Dumping	39%
Graffiti	40%
Medical Waste	50%

Let’s focus on the two biggest drops - graffiti and medical waste.

Where did all the graffiti go?

NYC is a mecca for street art, some of which is iconic, other that is a nuissance. Since 2021 there has been a focused effort to remove illegal graffiti around NYC. Despite the efforts, Highbridge Park remains a leading place to spot graffiti.

As an aside, I used to live near 5Pointz, which was demolished and converted into whitebox apartments where you can rent a studio for $4k a month. Conflicted feelings on that one…

Wait, medical waste?

Yes, medical waste. In fact there is a whole dataset devoted to tracking syringes in NYC(perhaps to be explored on a later date). Data on medical waste is a little suspect - in particular, in 2022 Marine Park far surpassed every other park for medical waste sightings, with more then 50% higher than Highbridge Park in second place, however in subsequent years sightings dropped to at or near 0. This harkens back to a terrifying incident in the 80’s called syringe tide, where medical waste washed up on CT, NJ, and NY shores, devastating local businesses.

Looking at the concentration of medical waste in our parks, looks like the current “leader” is Estella Diggs Park:

If the description of Estella Diggs Park is meant to be true - particularly “encourages kids and New Yorkers of all ages to come outside” - then perhaps it is an area to focus prevention efforts.

Where is this going from here?

It is great that there has been an overall drop in “filth” in our city. More can be done though - and in 2025 Mayor Adams established significant permanant funding for the Department of Sanitation to continue efforts to clean our parks, including the second shift program to provide daily focused cleaning efforts for our highest use areas. It seems optimistic that we should continue to see the trend towards cleaner parks, and a little less broken glass when you are lounging on those warm summer days.

Wifi in NYC

Thu, 25 Sep 2025 08:00:00 +0000

I preface this by admitting I am very late to the game - I have seemingly had my head buried in the sand as all of the LinkNYC stations went up around the city. It is not that I was not aware of them - they are nearly impossible to miss, with their digital ad displays, tablets (occasionally flashing explicit material…), and dubious looking plugs. I had not asked “why” though - and so here is what I found after a little digging.

There are 2308 of the hubs erected around the city, with 53% of them being located in Manhattan. There is sort of a patchwork distribution of them scattered around the 5 boroughs, with some heavy concentrations in the familiar areas.

Across the whole city, only 20% of census tracts have 1, while some (like in Red Hook or near Times Square) have many. In general, after removing a few outliers and controlling for population density, the distribution looks fairly reasonable.

How many would be needed to completely tile the city?

Each unit has an optimal range of about 150 ft and a maximum range of 400 ft. So assuming the units were optimally distributed, how many would it take to tile the whole city? 2308 seems like a lot, however it would actually require up to 119k of them to completely cover the city. Enter the the 5g variants of the towers, which have a range of 750 ft - we would only need 4740 of those to tile the city (ignoring for a second the difficulty those little 5g waves have in actually reaching people).

Internet for All

One of the objectives of the program was to provide internet to the least advantaged residents of NYC. The 5g program in particular seems to be targeting that - the 262 5g towers that have been built so far are generally distributed towards lower household income areas (on average, areas with 5g towers have 23% lower median income than standard towers).

Who Pays for this?

Advertisers! In fact, NYC appears to get a kickback from the program. In 2024 NYC booked $5.8M in revenue from the program, thanks in part to its contract to harvest 5% revenue LinkNYC makes from operating the digitial ad displays. Revenue is also harvested from leasing the 5g tower space to 3rd party carriers. Of course, this is all a little far off the astronomical initial projections, which was supposed to generate $500M over 12 years, but the deal was restructured in 2021 and appears to be smooth sailing now. Not bad for a municipal project!

What did we lose?

Phone Booths. The LinkNYC stations originated from a De Blasio program to replace the aging phone booths around the city. And it was successful in that - in 2022 the last phone booth was removed from 49th street and 7th ave. I suppose I am waiting now for Hollywood to do a reboot of Phone Booth centered around the LinkNYC stations.

Daycare in NYC

Sun, 04 Aug 2019 08:00:00 +0000

According to OpenData’s daycare inspection dataset, there are 2,948 daycare providers in NYC. That includes infant daycares, school based programs, and camps. Brooklyn has the lionshare of daycare centers - 1,255, or roughly 43% of all the daycare centers, with Manhattan coming in second (732, or 24%), and The Bronx third (430, or 14%).

Here is how the daycare centers are distributed around the city:

What is the best neighborhood to have a new baby in?

If you are interested in daycare, then it looks like you should be headed to Dumbo. The top five neighborhoods for the availability of infant daycare, controlling for population, are:

Neighborhood	People per Infant Daycare
DUMBO-Vinegar Hill-Downtown Brooklyn-Boerum Hill	3450
Midtown-Midtown South	4090
Battery Park City-Lower Manhattan	4411
Prospect Heights	4962
Clinton Hill	4970

This mostly correlates with stroller sightings around those neighborhoods (though Midtown, really?).

Where to go to camp?

Not surprisingly, camps look to be clustered around parks. The top neighborhoods with camps are:

Neighborhood	Number of Camps
Park Slope-Gowanus	24
East New York	12
Upper East Side-Carnegie Hill	11
East Harlem South	11
Central Harlem North-Polo Grounds	11

Park Slope has double the next most, but if you have visited Prospect Park in the summer this will not surprise you.

Where should there by more daycare centers?

Here is the plot of daycare centers throughout the city, controlling for population:

Notice anything? Looks like Queens is the outlier. Either there is a massive shortage of daycare centers in Queens, or daycare centers there are systemically under reported.

If we remove Queens from the data, the distribution looks more like this:

Looks like the neighborhoods with the lowest concentration of daycare centers are mostly in the Bronx. Here are the top five:

Neighborhood	Borough	People per Daycare
Arden Heights	Staten Island	12619
West Farms-Bronx River	The Bronx	11670
Stuyvesant Town-Cooper Village	Manhattan	10525
Parkchester	The Bronx	9940
Allerton-Pelham Gardens	The Bronx	9634

Presumably StuyTown is because of the high concentration of residential within that neighborhood. Still, the surrounding areas do not make up for it - perhaps a good place to start a daycare center?

Rats and Restaurants

Sat, 11 Nov 2017 18:00:00 +0000

NYC, like any city, has rats, and a lot of them - a study done in 2014 estimated that there are around 2 million rats who call NYC home. Most of those rats are the exotic Norwegian Rat (spoiler, they most likely did not actually come from Norway). But thanks to NYC’s Open Data portal, we can learn a lot more about our furry little cohabitants.

We can start by filtering the 311 data data to see the distribution of rat sightings around the city. In total, since 2010 there have been 78k rat sightings (and 25k mouse sightings) reported by New Yorkers. Which borough is the most rodent infested? That distinction goes to Brooklyn, with a combined 34k rat and mouse sightings reported. Then comes Manhattan with 27k, the Bronx with 21k, Queens with 15k, and last is Staten Island, with only 4.5k sightings. I guess rats don’t like commuting on the Staten Island ferry.

Rats versus mice

There are more then 3x as many rat reportings as there are mice reporting in NYC. But are they geographically distributed in the same regions? Are there “rat territories” and “mice territories” in the city? Turns out, yes - here is a plot of the difference in rat versus mice reporting by census tract. Areas in red have more rats being reported, areas in blue have more mice.

Rats appear to have a firm grip on most of Manhattan and Downtown Brooklyn, but as you get further out in Brooklyn and Queens there are spots where mice run the show.

When do rats show up?

Looks like they start scampering about around 10am, and then sightings taper off throughout the rest of the day. Note, this is based on human reported sightings, so perhaps New Yorkers are just most startled/disgusted by them in the morning, but when the evening rolls around they are used to them.

And rats tend to mingle when the weather is nicer outside. Below is the chart of the number of sightings in different months of the year - rat sighting peak in July, stay steady into October, and then drop precipitously for the winter.

What are we doing to stop them?

Recently De Blasio kicked off a $32 million rat reduction plan, so the rat population is definitely under attack. NYC offers up records of where they are doing their inspections and baitings, which allows us to isolate rat “safe zones” - areas where there are high concentrations of rat sightings, but low concentrations of inspections. Feel free to share this with your local community rat inspector (or with your rat population, depending on whose side you are on):

Rats are the most aggressively hunted in Manhattan; it has the most inspections or baitings (470k). There are spots within Brooklyn and Staten Island where there has historically been lower coverage despite high rat populations. And overall, Brooklyn has had only the third most inspections, 225k, less than half that of Manhattan. This runs counter to the fact that Brooklyn has 25% more rodent sightings reported than Manhattan. Maybe an area for some of that $32 million to go?

What cuisines do rats fancy?

Thanks to the restaurant inspections dataset we can see which NYC restaurants have had a problem with rodents at some point in their operation. Turns out, most restaurants have had an issue - 63% of all NYC restaurants have been cited at some point for either mice or rats being present in their facilities. But which cuisines do rats prefer the most?

The winner is Latin food, with 80% being cited for rodent problems. Caribbean (79% cited), Delicatessen (75% cited), Indian (75% cited), and Thai (74.5% cited) round out the top five cuisine types where you are most likely to run into a rat. Looks like rats generally stay away from juice and salad places (39% cited), as well as coffee (45% cited), and ice cream (46% cited).

I have to admit, I was really hoping that French food was going to top the list, but that is firmly in the middle, with 64% being cited.

What are rats worst enemy?

Apparently terriers - go figure.

Consensus in NY State Legislature

Sun, 22 Oct 2017 11:00:00 +0000

The NY state legislature’s voting record exposes an odd fact: they all almost always agree. The Open States Project organizes all of the available legislative voting data, so you can pull it down and see for yourself. For the past six years, in all but a handful of cases, every bill introduced for a floor vote is passed and usually with a margin of about 90%. How could this be?

Here is the agreement rate for the lower chamber of the legislature:

And here is the agreement rate for the upper chamber of the legislature:

This is a mystery, and I do not have a good answer. I would expect some healthy discord and debate, resulting in voting records indicating closer outcomes and more bills that failed to pass. Instead, voting records indicate that in the past 7 years only 4 bills failed their floor votes in the lower chamber, and only 1 in the upper chambers. That is out of a total of 7269 votes for the lower chamber (so a 0.06% failure rate) and 11155 votes for the upper chamber (less than a 0.009% failure rate). And as demonstrated above, when they pass (which is overwhelmingly most of the time), they pass with a super majority.

What could be going on here? Here are a couple of theories:

Voting is done in secret - votes could be conducted behind closed doors, without the record keeping that makes it transparent to the public. Seems unlikely, but if it were the case then they might only bring things to the floor which are certain to succeed.
Top party members dicate the vote - if all of the power brokering is done at the top, and votes are decided by the party leadership ahead of time, you might expect there to be little recorded discent in the actual votes. But this implies that most state legislatures are sheep, and their only impact is the weight they give to their party leader.
Voting no is is policitically non-viable - it could be the case that voting no on a bill is bad optics, and therefore every bill that makes it to a vote always gets a yes vote from everyone.

Or there is some other reason. But whatever the case may be, the consent and passage rate of the NY state legislature is a surprise, and challenges my assumptions of what a healthy democracy looks like.

A Tree Grows in NYC

Tue, 01 Aug 2017 20:00:00 +0000

Sometimes when it is hot out there is nothing more refreshing than escaping the heat in the shade of a tree. Luckily, in NYC there are thousands of trees planted along our streets, and NYC has done a great job in distributing them around the city. And better yet - thanks to the efforts of TreeCount NYC, we know the exact location and health of all of them!

The tree count is done once every 10 years, and the first time we have data for it is back in 1995. Since then, New Yorkers have planted close to 200,000 trees along the streets - thanks in part to initiatives like the million trees project. Nice job everyone! As of the 2015 count, there are 683,774 trees planted along our city streets. In an absolute sense, Queens ranks as #1 with 250,490 trees, Brooklyn is in second with 177,276 trees, and Staten Island takes the bronze with 105,317 trees (the Bronx has 84,880 and Manhattan rounds out the bottom, with 65,722 trees). Note, we are talking about trees planted along streets, so places like central park do not count.

Here is what the counts look like overall, broken down by census tract:

Since census tracts are of varying sizes, a slightly cleaner way to look at it is to consider it by density - if we normalize by the size of the census tract, we get the following:

The map makes some intuitive sense - there are high tree densities in mostly residential neighborhoods, whereas industrial areas (and airports) are much lower. And it is no surprise that the financial district and midtown have some of the lowest tree density rankings in the city. There is a bit of a conspicuous blight in southern Queens (in the Blissville/Laurel Hill neighborhoods), but those neighborhoods are very industrial.

Let’s zoom in on Brooklyn:

The BK neighborhood with the most street trees is… East New York, with 9603 trees! This is largely due to its size. When we normalize by area it drops to third place; the top 5 neighborhoods are Bookyn Heights (4690 trees/sq mile), Prospect Heights (4258 trees/sq mile), East New York (4222 trees/sq mile), Windsor Terrace (4170 trees/sq mile), and lastly, Williamsburg (4107 trees/sq mile). Coney Island bottoms out the list, with 1123 trees/sq mile, less than a quarter of the density of Brooklyn Heights. Lookup where your neighborhood ranks here.

I ran regressions/correlations comparing the tree counts in each area against other factors, like the age of the neighborhoods, the income of residents, demographic make up, etc. Somewhat surprisingly, only very weak relations emerged - suggesting that those factors do not play a part in where we decide to plant trees. The strongest relationship was with age of buldings, but even that was only -24% correlated with the number of trees planted in an area.

How to Get Involved

We can all help make our city a greener place - and after the next tree count in 2025 it would be nice to see the light spots in the maps above to get a little shade! Here are some ways you can get involved:

Request a Tree - you can ask NYC to plant a tree on your street, or plant one yourself!
Care for a tree in your neighborhood - Million Trees NYC gives workshops on how to care for trees in your area
Donate - there are a lot of good initiatives going on to make our city greener. And you can donate and get some fun swag at the same time!

AirBnB in the Lower Catskills

Sat, 10 Jun 2017 20:00:00 +0000

Its summer time, and that means its time to leave the city and head to the mountains, trails, cliffs, and rivers. First stop - Catskills! For today’s analysis let’s look at the rental market in the lower Catskills region. AirBnB has transformed the vacation rental market there in the past couple of years, but what drives a good rental property on AirBnB? What factors in that area lead to a property being able to fetch a higher price?

I took a look at AirBnB properties in three town in the southern Catskills - Pine Bush, Gardiner, and New Paltz. These towns are all around one of my favorite areas - the Mohonk Preserve. There are 136 properties, with a median rental price of $155 per night. New Paltz has the most, at 57 properties (median price $149), then Pine Bush (median price $165), and finally Gariner (median price $145). There are a couple of factors in a home rental that seem to drive the price.

Room Type

AirBnB offers up rentals for private rooms, shared rooms, and whole home rentals. In the Catskills, 63% of the homes are whole home rentals.

As expected, there is a big difference in price for whole home rentals ($195 median price) versus just a room ($100 median price).

Capacity

How many people a house can hold is the biggest factor in house price, and there is a pretty good linear relationship between capacity and price. The most prevalent property size is for 2 people (33% of all properties), because of the prevalence of single room rentals. Next is 4 person rentals (21%), then 6 person rentals (14%).

Interestingly, if we look at the relationship of capacity to rental price by town, we can see that Gardiner and New Paltz have a slight edge over Pine Bush.

Ratings

A big part of the AirBnB experience is the rating system. As a renter, you can rate your host on a number of factors. So how do these factors get reflected in rental prices? Looking at overall satisfaction, cleanliness, and communication, it appears like these ratings are a noisy contributor to the nightly price.

Instant Book

Some properties on AirBnB have the option to instantly book them, rather than going through the negotiation with the property owner/manager. For smaller properties there is not much of a difference, but for 6 person properties instant book homes are on average $67 more per night, and for 8 person homes they are on average $150 more per night. Overall, only about 20% of homes are listed as instant book.

Analysis

All of these factors independently contribute to the house rental price, but let’s build a combined pricing model to see how they interact together. I plugged the rental properties into a linear regression, minimizing the L2 norm with OLS. The scatter plot of the predicted price versus the actual price for the training data is plotted below:

The adjusted R-squared is .66, and the regression F-stat is 27.5. Most of the factors have t-stats over 2 - as mentioned above, the rating factors have the most noise.

If we translate the results of the regression into a more comprehensible pricing model, we end up with something like this:

The negative baseline is obviously unrealistic on its own, but with most pricing options added in the outcome becomes feasible (ie, positive). For instance, for a 3 bedroom house in Pine Bush with good reviews but no instant booking, the model predicts a nightly price of $311 = - $147 (baseline) + (6 x $55)(capacity) + ($7 + $15 + $9)(good ratings) + $21 (Pine Bush). Capacity is far and away the biggest driver of price, but this model has some interesting outcomes. For instance, instant book is worth quite a lot ($45 per night).

With a median price of $155 per night, there is really no reason not to go explore some of what the Catskills has to offer. Go check out the Mohonk Preserve, Minnewaska State Park, the Shawangunk Wine Trail, or the awesome tasting room at Angry Orchard.

Building Ages throughout Brooklyn

Mon, 27 Mar 2017 20:00:00 +0000

A quick tour through different neighborhoods in Brooklyn will take you through decades of construction and building styles. Thanks to the NYC OpenData project, and the Pluto dataset, we can put some numbers on exactly how old the builds are throughout our fair borough. Turns out, overall, Brooklyn clocks in with the oldest original construction date amongst all the boroughs of NYC - with a median construction year of 1931 (normalized to square footage). Manhattan is only slightly newer, at 1938.

Not surprisingly, building age is different throughout Brooklyn. Below we plot out the median building age by census tract, normalized to square footage.

The oldest neighborhoods are Ocean Hill (1911) and a four way tie between North Side-South Side, Cypress Hill, Park Slope, and Styvesant Heights - all with a median building year of 1920. The newest neighborhood is Coney Island (1969), followed by West Brighton (1962), East New York (1961), Canarsie (1960), and Williamsburg (1956). These are using the neighborhoods defined by NYC’s “neighborhood tabulation areas”.

Of course, the median age of buildings does not tell the whole story. When walking around a neighborhood like Park Slope you tend to notice not just that the building are old, but they are all old - there is a general consistency in the building age. Below is a map that attempts to capture that - measuring the diversity of building ages within Brooklyn neighborhoods (high diversity is darker, more consistency in age is lighter):

You can see that Park Slope is only in the middle of the pack. Neighborhoods like Brownsville and East Flatbush have the highest degree of homogenous construction age, whereas neighborhoods like Canarsie, Williamsburg, Greenpoint, and Fort Greene have a lot of variance - some new buildings sprouting up amongst the old.

New construction will most likely change how our neighborhoods look and feel, and 10 years from now these same maps will likely be entirely different. Brooklyn may even loose the title of the oldest borough overall. But I would wager there will still be enclaves of untouched, original construction for years to come - you just may have to venture further out in Brooklyn to find them!

Figure out your own home age

The statistics and figures here come from the Pluto dataset, so adventurous data enthusiasts can download the dataset themselves and search for their building. The dataset contains a wealth of information, including building type, zoning information, square footage, etc.

For an easier option, download this file: BK Addresses.xlsx and search for you address. It is setup with filters at the top which should help you narrow in on your street and house number. The file includes information on who the owner on record is, when it was built, and when it was last updated. Happy house hunting!

Methodology

So the Pluto dataset does not have the best of reputations. And I can see why - there are a lot of outliers and skews in the distributions. But I tried to control for this, and I think my results should still be valid. I did so in a couple of ways - I used medians whenever I could, winsorized the data before taking any aggregate, and aggregated to census tracts instead of looking at individual buildings. There are outliers, but in aggregate they should be filtered out. That said - if someone can explain some systematic bias in the data that would blow all this up, please share!