Do British cities have grid systems? We used science to find out

Some American cities with grid systems, yesterday. Image: Google Maps.

Grids! What are they good for? Basic urban planning, it turns out: take a look at how a US city is laid on a map, and often you’ll be looking at a grid of streets criss-crossing at exactly 90 degrees.

This is not strictly speaking an American phenomenon – similar systems have been used across the world for thousands of years because, well, it’s an easy way to divide up land. Fans of Worthing in West Sussex may be excited to learn that it owes some of its street layout to ‘centuriation’ – the grid system used by the Roman Empire.

But the US has really taken the idea and run with it, as you can see from these charts, which show the most common road orientations within a given city – the closer the chart is to a cross over the centre, the more closely aligned the city is to a grid. Just look at how dead on most of them are:

The street orientations of 25 US cities. Image: Geoff Boeing.

These charts are the work of urban planning researcher Geoff Boeing, who’s put together some software that can analyse the layout of the roads within a city, or any other geographical space, using data from OpenStreet Maps.

 

The streets of Manhattan, in map and polar histogram form. Image: Geoff Boeing.

Here he’s used the same process on 25 cities from around the world, which tend to be a lot less carefully laid out:

Image: Geoff Boeing.

Even where there isn’t a strict grid system, you can still usually make out an overall orientation if you squint – look at London, for instance.

London with some highly scientific lines drawn on it. Image: author’s own work.

When the City of London burned down in the great fire, the suggestions for how to rebuild it actually included various ideas for grid systems. It came to nothing, and the city ended up with broadly the same layout it had before it burned down – but if we use Boeing’s method, we can there is a pattern to the street orientation:

The City of London as a histogram. Image: author’s own work.

Which does make sense when you think about it – the roads either tend to follow the line of, or run down to, the river, thus: a grid.

Here’s the City together with the London boroughs:

The London boroughs as polar histograms of street orientation. Maps are so last year! Image: author’s own work.

What this doesn’t account for is size. Perhaps the larger the borough, the less likely it is to have a clear pattern – whether that be because it has several ‘competing’ grids or just is not going to be tied down with geometry, man. If we compare the City (1.12 square miles) and Bromley, the largest London borough (57.97 square miles), that seems plausible.

But that’s not necessarily true, because here are the boroughs in size order:

The London boroughs, now in size order. Image: author’s own work.

Lambeth is noticeably more of a jumble than its ‘size-neighbours’ Southwark and Camden, for instance.

And for that one guy who complains on Facebook that I only ever write about London, here are 25 UK towns and cities:

London plus 24 other weird places that aren’t London. Image: author’s own work.

But what about the most famous grid system in the UK, in Milton Keynes? Well, erm:

The Milton Keynes ‘grid system’. Image: author’s own work.

So does Milton Keynes have a grid system or not? Well, yes, but isn’t that strict.

Firstly, that’s because not every road is part of the grid – the ‘squares’ of the grid are the main roads and the smaller roads within don’t necessarily conform to any particular layout. And secondly, because it was deliberately designed not be as rigid as an American-style grid. In the words of David Lock, a planner who’s worked in Milton Keynes since the 1970s:

“The designers decided that the grid concept should apply but should be a lazy grid following the flow of land, its valleys, its ebbs and flows. That would be nicer to look at, more economical and efficient to build, and would sit more beautifully as a landscape intervention.”

Don’t worry though, grid fans, they did stick to a proper grid for the town centre.

Grids! Grids! Grids! Image: author’s own work.

Right, now for a rousing singalong of that classic post-war planning anthem: “You’ve never seen anything like it: Central Milton Keynes!”

Altogether now:

Ed Jefferson works for the internet and tweets as @edjeff.

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Urgently needed: Timely, more detailed standardized data on US evictions

Graffiti asking for rent forgiveness is seen on a wall on La Brea Ave amid the Covid-19 pandemic in Los Angeles, California. (Valerie Macon/AFP via Getty Images)

Last week the Eviction Lab, a team of eviction and housing policy researchers at Princeton University, released a new dashboard that provides timely, city-level US eviction data for use in monitoring eviction spikes and other trends as Covid restrictions ease. 

In 2018, Eviction Lab released the first national database of evictions in the US. The nationwide data are granular, going down to the level of a few city blocks in some places, but lagged by several years, so their use is more geared toward understanding the scope of the problem across the US, rather than making timely decisions to help city residents now. 

Eviction Lab’s new Eviction Tracking System, however, provides weekly updates on evictions by city and compares them to baseline data from past years. The researchers hope that the timeliness of this new data will allow for quicker action in the event that the US begins to see a wave of evictions once Covid eviction moratoriums are phased out.

But, due to a lack of standardization in eviction filings across the US, the Eviction Tracking System is currently available for only 11 cities, leaving many more places facing a high risk of eviction spikes out of the loop.

Each city included in the Eviction Tracking System shows rolling weekly and monthly eviction filing counts. A percent change is calculated by comparing current eviction filings to baseline eviction filings for a quick look at whether a city might be experiencing an uptick.

Timely US eviction data for a handful of cities is now available from the Eviction Lab. (Courtesy Eviction Lab)

The tracking system also provides a more detailed report on each city’s Covid eviction moratorium efforts and more granular geographic and demographic information on the city’s evictions.

Click to the above image to see a city-level eviction map, in this case for Pittsburgh. (Courtesy Eviction Lab)

As part of their Covid Resource, the Eviction Lab together with Columbia Law School professor Emily Benfer also compiled a scorecard for each US state that ranks Covid-related tenant protection measures. A total of 15 of the 50 US states plus Washington DC received a score of zero because those states provided little if any protections.

CityMetric talked with Peter Hepburn, an assistant professor at Rutgers who just finished a two-year postdoc at the Eviction Lab, and Jeff Reichman, principal at the data science research firm January Advisors, about the struggles involved in collecting and analysing eviction data across the US.

Perhaps the most notable hurdle both researchers addressed is that there’s no standardized reporting of evictions across jurisdictions. Most evictions are reported to county-level governments, however what “reporting” means differs among and even within each county. 

In Texas, evictions go through the Justice of the Peace Courts. In Virginia they’re processed by General District Courts. Judges in Milwaukee are sealing more eviction case documents that come through their courtroom. In Austin, Pittsburgh and Richmond, eviction addresses aren’t available online but ZIP codes are. In Denver you have to pay about $7 to access a single eviction filing. In Alabama*, it’s $10 per eviction filing. 

Once the filings are acquired, the next barrier is normalizing them. While some jurisdictions share reporting systems, many have different fields and formats. Some are digital, but many are images of text or handwritten documents that require optical character recognition programs and natural language processors in order to translate them into data. That, or the filings would have to be processed by hand. 

“There's not enough interns in the world to do that work,” says Hepburn.


Aggregating data from all of these sources and normalizing them requires knowledge of the nuances in each jurisdiction. “It would be nice if, for every region, we were looking for the exact same things,” says Reichman. “Instead, depending on the vendor that they use, and depending on how the data is made available, it's a puzzle for each one.”

In December of 2019, US Senators Michael Bennet of Colorado and Rob Portman of Ohio introduced a bill that would set up state and local grants aimed at reducing low-income evictions. Included in the bill is a measure to enhance data collection. Hepburn is hopeful that the bill could one day mean an easier job for those trying to analyse eviction data.

That said, Hepburn and Reichman caution against the public release of granular eviction data. 

“In a lot of cases, what this gets used for is for tenant screening services,” says Hepburn. “There are companies that go and collect these data and make them available to landlords to try to check and see if their potential tenants have been previously evicted, or even just filed against for eviction, without any sort of judgement.”

According to research by Eviction Lab principal Matthew Desmond and Tracey Shollenberger, who is now vice president of science at Harvard’s Center for Policing Equity, residents who have been evicted or even just filed against for eviction often have a much harder time finding equal-quality housing in the future. That coupled with evidence that evictions affect minority populations at disproportionate rates can lead to widening racial and economic gaps in neighborhoods.

While opening up raw data on evictions to the public would not be the best option, making timely, granular data available to researchers and government officials can improve the system’s ability to respond to potential eviction crises.

Data on current and historical evictions can help city officials spot trends in who is getting evicted and who is doing the evicting. It can help inform new housing policy and reform old housing policies that may put more vulnerable citizens at undue risk.

Hepburn says that the Eviction Lab is currently working, in part with the ACLU, on research that shows the extent to which Black renters are disproportionately affected by the eviction crisis.

More broadly, says Hepburn, better data can help provide some oversight for a system which is largely unregulated.

“It's the Wild West, right? There's no right to representation. Defendants have no right to counsel. They're on their own here,” says Hepburn. “I mean, this is people losing their homes, and they're being processed in bulk very quickly by the system that has very little oversight, and that we know very little about.”

A 2018 report by the Philadelphia Mayor’s Taskforce on Eviction Prevention and Response found that of Philadelphia’s 22,500 eviction cases in 2016, tenants had legal representation in only 9% of them.

Included in Hepburn’s eviction data wishlist is an additional ask, something that is rarely included in any of the filings that the Eviction Lab and January Advisors have been poring over for years. He wants to know the relationship between money owed and monthly rent.

“At the individual level, if you were found to owe $1,500, was that on an apartment that's $1,500 a month? Or was it an apartment that's $500 a month? Because that makes a big difference in the story you're telling about the nature of the crisis, right? If you're letting somebody get three months behind that's different than evicting them immediately once they fall behind,” Hepburn says.

Now that the Eviction Tracking System has been out for a week, Hepburn says one of the next steps is to start reaching out to state and local governments to see if they can garner interest in the project. While he’s not ready to name any names just yet, he says that they’re already involved in talks with some interested parties.

*Correction: This story initially misidentified a jurisdiction that charges $10 to access an eviction filing. It is the state of Alabama, not the city of Atlanta. Also, at the time of publication, Peter Hepburn was an assistant professor at Rutgers, not an associate professor.

Alexandra Kanik is a data reporter at CityMetric.