In the Suburbs of Flatsville, Arkowa

Our field trip to the suburbs continues in our One Thousand Villages series of wildcat city planning.

Arkowa is a state in the American Midwest, where the legislature has graciously agreed to give our new Metropolitan Planning Authority control over an area of land to build a new city, off of a major highway.  According to the news this is somehow tied into a scandal involving a group of climate vigilantes holding thousands of tractors hostage using a backdoor in hacked Ukrainian tractor firmware, but the news hasn’t been very reliable lately, so such suspicions can be safely disregarded.

Here we have a suburban klick, broken into four quads of various densities.

With American development comes the American love of the automobile.  Many of our new residents are commuting to the neighboring city of Springfield for work, travelling along the highway, and there are limits to just how far we can stretch our city’s public transport infrastructure!  

In the interests of keeping our quads safe, quiet, pleasant, and efficient, however, we want to avoid paving them over with dense roads that discourage foot and bicycle traffic.  Eventually they will have more development, and we want residents to be able to walk to stores on the outer edge without once entering a car.

As such, our klick has two input roads and two output roads, with parking near the center.  Each morning, rather than a traffic jam as some cars wait to make a left turn, instead all of the cars exit from the parking lot on one dedicated lane per quad.  The turning lanes onto the main road are also lengthy, with almost enough room for every car in each quad, which means they won’t jam, either.  If the outer main roads are four lanes, then each lane can turn either left or right with no need to switch before leaving the klick.

In the evening, the dedicated collector lanes lead straight into each quad’s parking lot.  Through traffic avoids the interior of the klick almost entirely, as travel through a klick always changes your direction by 90 degrees.  Extra space for more lanes later with further development is reserved as green space.

Now let’s talk about the quads themselves.

Moneybrook Farms is a gated community with between 16-48 residents, dominated by a number of very large houses with very large lawns, for rich people.  It would give us a very sparse 48-192 residents per kilometer, which is going to have trouble supporting much infrastructure.  Fortunately, if they’re part of our greater grid, we can levy enhanced property taxes on their high property values to offset their low density.

Brightlawn Gardens consists entirely of 20x20m housing.  It has a population of 96-192.  An entire klick of this density would have a population between 384 and 768 per kilometer.  Enough to support a store?  Maybe.  If each resident buys groceries twice a week, our hypothetical grocer gets about 164 customers per day.

Fairlawn (106-212) is similar to Brightlawn Gardens, but has a mix of housing types instead of just 20x20m housing.  On the other hand, it has no row houses.  Density considerations are similar.

Deerfield Village is much denser.  With 264-528 residents, it’s over twice as dense as Fairlawn, and an order of magnitude denser.  A Deerfield klick would have a population between 1,056 and 2,112, which should be enough to support our grocery store (452 visits/day), or civic infrastructure such as a small school.  And while the row houses may look small, they have a floor area of 10x20x2m - 400 square meters (4,300 sqft), which is quite a lot!  They should also have favorable noise properties compared to apartments, or could be built twice as dense and still have quite a comfortable size.

Deerfield Village also begins to open up our public transit options.  Big US cities spend about $2600 per resident.  Supposing we spend 10% of that on our public transport network, a Deerfield klick has between $274,560 and $549,120 for public transit.  A city bus costs about $400,000 and lasts about 12 years (or about $34,000 relative to our annual spending), and it costs around $150/hr to operate.  So if we run our bus 8 hours a day (perhaps in 2-3 hour windows), it costs us about $472,000 annually, which could potentially be supported just by one kilometer of this density.  (The required number of buses and throughput of the bus network depend on a lot more information than we have here.)