The problem of space: why Elon Musk doesn't understand urban geometry

Elon Musk unveils the new Tesla Model X Crossover SUV in Fremont, California, last September. Image: Getty.

He may be a brilliant visionary in all kinds of ways, but Elon Musk’s “Master Plan, Part Deux” makes grand plans for the abolition of fixed route public transport without thinking clearly about urban space:

“With the advent of autonomy, it will probably make sense to shrink the size of buses and transition the role of bus driver to that of fleet manager. Traffic congestion would improve due to increased passenger areal density by eliminating the center aisle and putting seats where there are currently entryways, and matching acceleration and braking to other vehicles, thus avoiding the inertial impedance to smooth traffic flow of traditional heavy buses.

“It would also take people all the way to their destination. Fixed summon buttons at existing bus stops would serve those who don’t have a phone. Design accommodates wheelchairs, strollers and bikes.”

Musk assumes that public transit is an engineering problem, about vehicle design and technology.  In fact, providing cost-effective and liberating transportation in cities requires solving a geometry problem, and he’s not even seeing it.  What’s more, he’s repeating a very common delusion, one I hear all the time in urbanist and technology circles.

Musk’s vision is fine for low-density outer suburbia and rural areas.  But when we get to dense cities, where big transit vehicles are carrying huge ridership, Musk’s vision is a disaster.  That’s because it takes lots of people out of big transit vehicles and puts them into small ones, which increases the total number of vehicles on the road at any time.  The technical measure of this is Vehicle Miles (or KM) Travelled (VMT).

Today, increasing VMT would mean increased emissions and increased road carnage. But let’s say technology has solved those problems, with electric vehicles and automation.  Those are engineering problems.  Inventors can work on those.

There is still, and will always be, the problem of space. Increasing VMT means that you are taking more space to move the same number of people. This may be fine in low-density and rural areas, where there’s lots of space per person.  But a city, by definition, has little space per person, so the efficient use of space is the core problem of urban transportation.

The tyranny of maths

When we are talking about space, we are talking about geometry, not engineering, and technology never changes geometry.  You must solve a problem spatially before you have really solved it.

The reigning fantasy of Musk’s argument is that we must always “take people all the way to their destination”. But to do this we must abolish the need to ever change vehicles – from a train to a bus, from a car to a train, from a bus to a bike – and of course we also abolish walking.  This implies a vision in which buses are shrunk into something like taxis, because a vehicle going directly from your exact origin to your exact destination at your chosen time won’t be useful to many people other than you.

So a bus with 60 people on it today is blown apart into, what, little driverless vans with an average of three each, a 20-fold increase in the number of vehicles?  It doesn’t matter if they’re electric or driverless.  Where will they all fit in the urban street?  And when they take over, what room will be left for wider sidewalks, bike lanes, pocket parks, or indeed anything but a vast river of vehicles?

There are audiences for which Musk’s vision makes mathematical sense sense: people for whom useful high-ridership transit isn’t an option anyway.  There are two big categories of these people:

  • People who live in outer-suburban and rural areas, where space is abundant and high-ridership transit isn’t viable;
  • The top 20 per cent or so of urban residents, who can afford to use relatively expensive servies that would never scale to the entire population of the city.

If you are in one of these categories, your most urgent task is to remember that most people aren’t like you, and that cities are impossible if everyone lives according to your personal tastes.  As Edward Glaser said, “one’s own tastes are rarely a sound basis for public policy”.

That issue, right there, is the great disconnect between tech marketing and genuine urban problem-solving.


Tech marketing is all about appealing to elite personal tastes.  It runs on the assumption that whatever we sell to the wealthy today we can sell to the masses tomorrow.  

But some things stop working when everybody buys them. Cars in dense cities, for example, are not a problem when only the top 20 per cent are using them; it’s mass adoption of cars that makes them ruinous to a dense city and to the liberty of its citizens. Ask anyone in a fast-growing developing world city about that.

Here is the harm that this all this elite chatter about abolishing the bus is doing: it’s introducing fatal confusion into the discussion of urban development.

The density solution

Dense cities that want to live in the real world of space and time, and that do not want to become dystopias that are functional only for the rich, need to use urban space efficiently. There is some simple and well-proven maths about how to do this, which is also the maths of how transit systems achieve high ridership.

These cities need to organize themselves around frequent transit corridors, where big-vehicle frequent transit, bus or rail, can prosper, allowing the city to grow dense without growing vehicle trips.

Someday some of these corridors will be rail or Bus Rapid Transit. But the only way to grow enough corridors quickly, so that you cover much of the city with frequent service that can succeed in ridership terms, is to take frequent fixed-route bus service seriously. If you don’t do that in your land use planning, you’re going to end up building a city where fixed transit is geometrically impossible, and then you’ll have to settle for Musk’s vision. Geometrically, that vision can only mean liberating transportation just for the top 20 per cent – or electrified, automated gridlock for everyone.

Smart cities aren’t just the ones that chase the latest technology fads. They’re the ones that think carefully about the spatial, geometric problem that a dense city is. Because if it doesn’t work geometrically, it doesn’t work.

Jarrett Walker is an international consultant in public transit network design and policy, based in Portland, Oregon. He is also the author of “Human Transit: How clearer thinking about public transit can enrich our communities and our lives".

This article was originally written for his blog, and is reposted here with permission.

 
 
 
 

Mexico City’s new airport is an environmental disaster. But it could become a huge national park

Mexico City’s new Norman Foster-designed airport, seen here in a computer rendering, is visually striking but environmentally problematic. Image: Presidencia de la República Mexicana/creative commons.

Mexico City long ago outgrew the two-terminal Benito Juárez International Airport, which is notorious for delays, overcrowding and canceled flights. Construction is now underway on a striking new international airport east of this metropolis of 20m. When it opens in late 2020, the LEED-certified new airport – whose terminal building was designed by renowned British architect Norman Foster in collaboration with the well-known Mexican architect Fernando Romero – is expected to eventually serve 125m passengers. That’s more than Chicago O'Hare and Los Angeles’ LAX.

But after three years of construction and $1.3bn, costs are ballooning and corruption allegations have dogged both the funding and contracting process.

Environmentalists are also concerned. The new airport is located on a semi-dry lake bed that provides water for Mexico City and prevents flooding. It also hosts migrating flocks and is home to rare native species like the Mexican duck and Kentish plover.

According to the federal government’s environmental impact assessment, 12 threatened species and 1 endangered species live in the area.

The airport project is now so divisive that Andrés Manuel López Obrador, the populist winner of the country’s 2018 presidential campaign, has suggested scrapping it entirely.

An environmental disaster

Mexico’s new airport sits in a federal reserve. Image: Yavidaxiu/The Conversation.

I’m an expert in landscape architecture who studies the ecological adaption of urban environments. I think there’s a way to save Mexico’s new airport and make it better in the process: create a nature reserve around it.

Five hundred years ago, lakes covered roughly 20 percent of the Valle de Mexico, a 3,500-square-mile valley in the country’s south-central region. Slowly, over centuries, local residents – first the Aztecs, then the Spanish colonisers and then the Mexican government – built cities, irrigation systems and plumbing systems that sucked the region dry.

By the mid-20th century, the lakes had been almost entirely drained. In 1971, President Luís Echeverría decreed the area a federal reserve, citing the region’s critical ecological role for Mexico City. The smattering of small lakes and reforested land there now catch and store runoff rainwater and prevent dust storms.

The new airport will occupy 17 square miles of the 46-square-mile former Lake Texcoco. To ensure effective water management for Mexico City, the airport master plan proposes creating new permanent water bodies to offset the lakes lost to the airport and cleaning up and restoring nine rivers east of the airport. It also proposes planting some 250,000 trees.

The government’s environmental assessment determined that the impacts of the new airport, while significant, are acceptable because Lake Texcoco is already “an altered ecosystem that lost the majority of its original environmental importance due to desiccation and urban expansion.” Today, the report continues, “it is now only a desolate and abandoned area.”

Environmentalists loudly disagree.

Make Mexico’s airport great again

I see this environmental controversy as an opportunity to give Mexico City something way more transformative than a shiny new airport.

Nobody can entirely turn back the clock on Lake Texcoco. But the 27 square miles of lake bed not occupied by the airport could be regenerated, its original habitat partially revitalised and environmental functions recovered in a process known as restoration ecology.

I envision a huge natural park consisting of sports fields, forests, green glades and a diverse array of water bodies – both permanent and seasonal – punctuated by bike paths, walking trails and access roads.

The airport will come equipped with new ground transportation to Mexico City, making the park easily accessible to residents. Extensions from the surrounding neighborhood streets and highways could connect people in poor neighbourhoods abutting the airport – dense concrete jungles like Ecatepec, Ciudad Nezahualcoyotl and Chimalhuacan – to green space for the first time.

The nine rivers that empty into Lake Texcoco from the east could be turned into greenways to connect people from further out in Mexico State to what would become the area’s largest public park.

Space could also be reserved for cultural attractions such as museums, open and accessible to passengers in transit.


New master plan

This idea is not as crazy as it sounds.

As early as 1998, Mexican architects Alberto Kalach and the late Teodoro González de León proposed rehabilitating the lakes of the Valley of Mexico. Their book, “The City and its Lakes,” even envisaged a revenue-generating island airport as part of this environmentally revitalized Lake Texcoco.

Under President Felipe Calderon, Mexico’s National Water Commission also proposed building an ecological park in Lake Texcoco, which was to include an island museum and restore long-degraded nearby agricultural land. But the project never gained traction.

Granted, turning a large, half-constructed airport into a national park would require an ambitious new master plan and a budget reallocation.

But in my opinion, evolution and change should be part of ambitious public designs. And this one is already expected to cost an additional $7.7bn to complete anyway.

Toronto’s Downsview Park – a 291-acre former air force base turned green space – has transformed so much since its conception in 1995 that its declared mission is now to “constantly develop, change and mature to reflect the surrounding community with each generation.”

Local communities neighboring Mexico City’s new airport were not adequately consulted about their needs, environmental concerns and their current stakes in the Lake Texcoco area. A revamped park plan could be truly inclusive, designed to provide recreation and urban infrastructure – and maybe even permanent jobs – for these underserved populations.

Presidential race

Three of the four candidates in Mexico’s July 1 presidential election wanted to finish Mexico City’s new international airport. But eventual winner López Obrador was not so sure.

Early in his campaign, he said he would cancel it if elected. Instead, López Obrador suggested, a former air force base could become the new international terminal. It would be connected to Benito Juárez airport, 22 miles south, by train.

López Obrador has since said he would support completing construction of the new international airport if the remaining financing came from the private sector, not the Mexican government. Currently, some two-thirds of the project is funded by future airport taxes.

The ConversationLópez Obrador’s promise to review and likely upend the airport plan could open the door to its wholesale transformation, putting people and nature are at the core of a plan ostensibly designed for the public good.

Gabriel Diaz Montemayor, Assistant Professor of Landscape Architecture, University of Texas at Austin

This article was originally published on The Conversation. Read the original article.