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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Marseille and Paris are crawling with rats. But it’s your problem too

A Parisian rat. Image: Getty.

You can very easily have a fine time in Marseille, but it is likely to be interrupted by rats.

The bloated and brazen beasts are so utterly convinced they own the place that they barely register any human presence to distract from their hedonistic excesses – throwing wild street parties, burrowing holes in overflowing bins, and darting in and out of exclusive harbourfront restaurants. We only really intrude when the occasional, blissfully oblivious rat is splattered across the cobblestones by a scooter.

For many residents, the whiskery foes have gone some way beyond a nuisance to represent a genuine menace. Rats have infested schools and taken over canteens. Pest control services claim they have broken into cars and gnawed through cables, which may have contributed to accidents. It is also alleged that they have caused Internet outages by attacking fibre-optic cables – continuing the venerable horror movie tradition of cutting the power seen in Aliens and Jurassic Park. Rats are also infamous and prolific traffickers of disease and have raised the threat of Leptospirosis.

Rat populations are fiendishly difficult to quantify, given their nocturnal lifestyle and that many live off-grid in the sewers; but by some estimates they now outnumber Marseille’s human inhabitants. Distress calls from the public to the city’s sanitation department and pest control services have increased, and the unofficial fifth emergency service has expanded its operations in response, laying poison traps and sweeping the gutters.

Several factors have contributed to the rat supremacy. Marseille’s Mediterranean climate has always been hospitable to rats, and a series of unusually warm summers – often passing 30°C – have made it more so. (Rats tend to stop breeding when it’s cold.)

City officials also bemoan the wanton waste disposal habits of their citizens, which have allowed large and easily accessible piles of appetising trash to accumulate. Marseille’s councillor for hygiene Monique Daubet recently complained the city has become a “five-star restaurant for rats”.

Others have suggested a series of strikes by garbage collectors gave the rat population a turbo charge it barely needed. A single pair of brown rats can spawn more than a thousand descendants within a year.

That formidable birth rate is one indicator of what the city is up against: the urban rat is almost a perfect predator. Millennia of human ingenuity has failed to remove them from our midst or negate the threats they pose. Rats are supreme survivors – scientists marvel at their survival on nuclear test sites – and they thrive in the most inhospitable environments. They can eat practically anything, but are neophobic, meaning they shy away from all but the most devious poison traps. The rodents are intelligent, resilient, and their ability to colonise new habitats rivals our own.

Faced with this adversary, the local authority has assigned more resources to the fight, through both the city’s sanitation department and the private extermination service A3DS. Both are reluctant to discuss their tactics and whether they are having an impact. But officials are also taking a tough line on public responsibility, insisting that residents dispose of trash after 7pm in sealed bags or face fines. The city has also proposed measures such as mobile dumps and new model bins that rats should find harder to access.

The Marseillais are also keeping a close eye on events in the capital: Paris’ rat problem may be even more severe, driven by flooding from the River Seine that has forced the rodents to seek higher ground. In recent years, rats have overrun the Louvre and forced the closure of public parks, as well as starring in viral video nasties that do little for the city’s image as the capital of romance.


Paris mayor Anne Hidalgo has sounded the alarm and invested millions of euros in a campaign against rats, which has seen thousands of raids in hundreds of parks and buildings, as well as the introduction of more secure bins, and fines levied against people accused of feeding the enemy. Her administration has also despatched an envoy to New York to study the city’s approach to its own notorious rodent community.

An international approach makes sense given that rats are on the march all around the world. Reported sightings have shot up in New York, Chicago, Boston, San Francisco, and Washington. One study estimated that rats inflict $19 billion of economic damage each year in the US alone. London has also seen an increase in reported sightings. Leading rodentologist Bobby Corrigan says the same patterns are playing out in the major cities of the Americas, Europe, Asia, and Australia.

And for much the same reasons. Contributing factors include “too few resources allocated an organised program for rat control,” says Corrigan. “Also, more people in our cities means more refuse, more overloading of the city’s sanitation budgets, less thorough removal of the kind of food shrapnel that escapes typical garbage collection. Each rat only needs about 30 grams of food per 24 hours to thrive and reproduce.” A warming climate also plays a part.

Poison traps and culls can only go so far, says the rodentologist, arguing that a holistic approach is required to head off the growing threat. “The best measure is a city organised in addressing the rats across all agencies,” says Corrigan. That means mobilising departments of sanitation, parks, housing, health, and sewers, as well as mayoral administrations themselves.

Society-wide civic participation is also essential. “Controlling rats takes everyone: every homeowner, shop owner, restaurant, grocery store, airport, and so on. Not to do so invites the risk of a “new and/or highly virulent virus” developing among our old enemies, he adds.

Research into sterilisation programmes offers some hope of a new weapon to repel and reduce the rodent hordes. But not enough for us to evade responsibility while rat populations grow and the threat increases. “If we don’t work together as the wise species we claim to be and present a scientific, multi-faceted organised effort against this very smart and organised smaller mammal, we can have no hope of defeating it,” says Corrigan. Time to man the barricades.