15 Ideas That Have Helped Shape American Cities


Cities are living things, forever changing and adapting. Over decades and centuries, people have adapted their towns to look and function in certain ways, to ease traffic, maintain a certain visual identity, or improve business. Psychology, local climate, politics, and pure whim all dictate how cities develop over time. Here are 15 reasons the urban world looks and feels the way it does today:

1. As long as there have been cities, there has been an urban grid

Some of the world’s oldest cities were built along grid plans still in use today. Ancient China, Mesopotamia, and Greece [PDF] all had arranged city streets with some version of the north-south and east-west orientations (intersecting at right angles in a chessboard pattern) found in modern metropolises like Chicago. While plenty of ancient cities boasted the twisting, curving alleys of tourists’ nightmares, Hippodamus of Miletus, the “father of city planning,” argued for a more logical organization for cities in the 5th century BCE, calling for geometric streets with public space, markets, government buildings, and houses of worship all centrally located.

2. The ideal length for a city block is about 200 feet

A block in Athens, GreeceiStock.com/Starcevic

Why do some neighborhoods feel like they take longer to walk around in than others? It’s all about perception. Short blocks make a more comfortable walk, because the scenery changes more often. The ideal city block offers a new route choice about once every minute, according to the Bay Area urban planning nonprofit SPUR [PDF]. This equates to about once every 200-300 feet—the length of a city block in pedestrian-friendly cities like Portland, Oregon.

3. Truly safe speed limits are slower than you'd think

In 2014, Paris set the default speed limit for its streets at less than 20 mph, following a trend embraced by numerous European municipalities. In busy cities, lower speed limits can actually improve congestion, as they help maintain the flow of traffic [PDF]. And lower speed limits dramatically reduce the potential for deadly accidents between cars and pedestrians. In a study by the U.S. National Highway Traffic Safety Administration, only 1.2 percent of accidents between people and cars going less than 20 mph were fatal, compared to over 22 percent of pedestrian accidents involving cars going 50 mph.

4. Entire towns have banned clotheslines, leaving backyards laundry-free

The old-fashioned method of hanging your laundry out to dry in the sun hasn’t just gone out of fashion as electric dryers gained steam. Some communities have eliminated the sight of laundry hanging around town through more direct means. In Levittown, Pennsylvania, for instance, one of the earliest models of the post-war American suburb, they were banned because “old fashioned clothes lines strung across the lawn look messy,” according to the town’s developer, William Levitt. In 2010, the BBC estimated that 60 million Americans lived in "about 300,000 communities governed by home-owning associations," many of which ban clotheslines as an eyesore—so many that multiple states have passed laws saying you can’t be prohibited from hanging your clothes in the sun. 

5. Highways aren’t lined with trees because too many people hit them

The U.S. Department of Transportation reports that trees are the most commonly struck objects in serious roadside crashes. California’s transportation administration, for instance, mandates that all trees be set back at least 30 feet from the road [PDF]. However, whether or not trees actually cause crashes is more controversial. Some urban designers argue that clearing highways of trees makes people drive faster in the first place [PDF], but that line of thinking has yet to become popular enough to re-landscape our freeways.

6. That big parking lot is required by the city


America’s love affair with parking (and lack of widespread mass transit) means that wherever people go, they need to find parking—even at bars, where arguably no one should be driving. Most cities mandate a certain number of off-street parking spaces be built for each new development based on estimates of peak demand. For instance, Cincinnati requires one parking space for every 1,200 square feet of office space. In Austin, a longtime neighborhood restaurant nearly shut down in 2013 because it didn’t provide 50 parking spaces for employees and customers, the city minimum.

7. Diagonal crosswalks keep drivers from turning on top of pedestrians and each other

Drivers tend to dislike them because they result in longer red lights, but diagonal crosswalks—where all vehicles stop at once to allow for unfettered walking access across the intersections—have proven to reduce pedestrian accidents, especially in intersections with a lot of pedestrian traffic. Perhaps the most famous of these crosswalks is Tokyo’s Shibuya crossing, one of the world’s busiest intersections. The diagonal crosswalk (also known as scrambles or “Barnes dances” after a traffic engineer who popularized them in Denver) is making a comeback in the U.S., too, in cities like Los Angeles, Chicago, and San Francisco.

8. Zoning laws arose to try to distance low-brow manufacturing from upscale shopping

In 1916, New York City passed the first comprehensive zoning ordinance in the U.S. [PDF]. Besides regulating tall buildings, it divided the city into residential, business, and unrestricted districts. In business districts, distasteful trades like manufacturing, auto repair, and metalwork were prohibited. A major player behind the law was the Fifth Avenue Association, which was formed in 1907 to stop factory encroachment on the fashionable boulevard. The high-end retailers of Fifth Avenue did not want lowly garment workers shooing away ladies from their shopping [PDF].

9. Does your neighborhood suddenly have a lot of rock gardens? The city paid for that

In drought-stricken Southern California, major cities have begun offering incentives for residents to ditch their thirsty grass lawns. Los Angeles gives property owners rebates for every square foot of lawn they rip up and replace with a drought-friendly option like succulents, getting rid of 1.5 million square feet of grass between 2009 and 2013. In 2014, they upped the kickback for switching to climate-appropriate plants to $3.75 per square foot for up to 1500 square feet, and 2 dollars per square foot after. Other cities, including Pasadena, Long Beach, and Anaheim participate in similar schemes.

10. That new pedestrian plaza owes its design to a snowstorm

After a heavy snow, plows pile snowbanks up around the edges of streets, narrowing the lanes cars can use. For urban designers, these snow tracks illustrate the amount of space cars actually use in an intersection, versus what’s essentially open space. Named after a term for curb extensions—"neckdowns"—these so-called sneckdowns (portmanteau of snow and neckdown) are occasionally used to redesign streets long after the snow has melted to calm traffic and make more room for pedestrians. In Philadelphia, for instance, images of snow-covered streets resulted in approval for more crosswalks and new pedestrian islands at one large intersection.

11. Danger levels determine how many sides a traffic sign has

In the early days of traffic safety, traffic engineers decided sign shapes should indicate the level of danger present in a particular situation. More sides meant more danger. As a result, railroad crossings became round (infinite sides) and stop signs became octagonal, showing drivers that these intersections were treacherous. By contrast, diamond signs alerted drivers that they merely needed to be cautious, and rectangular signs provided non-essential information like directions. The theory was, in an era before reflective coatings and widespread illumination, drivers could respond to a sign’s shape even if they couldn’t read it in the dark.

12. Washington, D.C. buildings can only be as tall as their street is wide


The capital’s buildings are regulated by the Height of Buildings Act of 1910, which maintains that no tower shall rise more than 20 feet taller than the width of the street it faces, and zoning in some neighborhoods prohibits even reaching that height. On certain streets, the 1910 law allows the “extreme height” of 160 feet tall. In recent years, as D.C.’s population and real estate prices have soared, this cap on skyscrapers has become controversial as one of the main drivers of the city’s extremely high rents.

13. New York City marketed Broadway as a theater district to keep it from getting too raunchy

In 1967, New York City passed an ordinance allowing a 20 percent bonus in buildable floor area in new developments if a new theater was also incorporated into the plan, hoping to encourage the growth of more wholesome entertainment in contrast to Times Square’s rising wave of porn shops and prostitution. In the late 1980s, eager to attract new builders while still retaining the vibrancy of a theater district, city officials mandated that all new developments near Broadway allocate a certain percentage of floor space to “entertainment-related uses,” including rehearsal studios, theaters, and costume shops [PDF].

14. Hollywood has palm trees because they made for neater sidewalks

Before the 1930s, the iconic Southern California tree wasn’t a palm, it was a pepper tree. Environmental historian Jared Farmer tells LA radio station KCET this story of L.A.’s transformation into a palmy paradise:

In the age of streetside parking, sidewalks, sewers, and utility poles, these leafy, rooty growers acquired bad reputations. In contrast, palms held out the promise of symbiotic infrastructure: they could provide beautification without dropping fruit, buckling concrete, or breaking pipes and wires.

The Mexican fan palm, the tall, skinny trees that have become an iconic symbol of Hollywood, were chosen because they were cheap and resilient. Hollywood became the dominant force in entertainment around the same time when L.A.’s Depression-era trees matured, cementing the region’s association with the palm with savvy marketing.

15. Colored bike lanes are green to keep people from thinking they're disability parking

In 2011, the Federal Highway Administration gave its interim approval for cities to use green colored pavement to mark bicycle lanes. While there’s no international standard for bike lane colors (London uses blue, the Netherlands uses red), the U.S. decided to go with green, as in, wow, biking sure is good for the environment!

A report [PDF] from the Chicago Department of Transportation sums the rationale up this way:

While CDOT’s findings show that blue is the most tested and widely associated color for colored bike lanes, due to its current association with parking spaces for persons with disabilities, CDOT feels it is unsuitable for colored bike lane pavement markings. Green, on the other hand, is not assigned a meaning for pavement markings in this country.

According to the FHWA’s approval notice, red pavement for bicycling infrastructure is still being tested. Too bad for Portland, Oregon, which pioneered colored bike lanes in the U.S. in the late ‘90s but went with the color blue [PDF].

The 10 Best Air Fryers on Amazon


When it comes to making food that’s delicious, quick, and easy, you can’t go wrong with an air fryer. They require only a fraction of the oil that traditional fryers do, so you get that same delicious, crispy texture of the fried foods you love while avoiding the extra calories and fat you don’t.

But with so many air fryers out there, it can be tough to choose the one that’ll work best for you. To make your life easier—and get you closer to that tasty piece of fried chicken—we’ve put together a list of some of Amazon’s top-rated air frying gadgets. Each of the products below has at least a 4.5-star rating and over 1200 user reviews, so you can stop dreaming about the perfect dinner and start eating it instead.

1. Ultrean Air Fryer; $76


Around 84 percent of reviewers awarded the Ultrean Air Fryer five stars on Amazon, making it one of the most popular models on the site. This 4.2-quart oven doesn't just fry, either—it also grills, roasts, and bakes via its innovative rapid air technology heating system. It's available in four different colors (red, light blue, black, and white), making it the perfect accent piece for any kitchen.

Buy it: Amazon

2. Cosori Air Fryer; $120


This highly celebrated air fryer from Cosori will quickly become your favorite sous chef. With 11 one-touch presets for frying favorites, like bacon, veggies, and fries, you can take the guesswork out of cooking and let the Cosori do the work instead. One reviewer who “absolutely hates cooking” said, after using it, “I'm actually excited to cook for the first time ever.” You’ll feel the same way!

Buy it: Amazon

3. Innsky Air Fryer; $90


With its streamlined design and the ability to cook with little to no oil, the Innsky air fryer will make you feel like the picture of elegance as you chow down on a piece of fried shrimp. You can set a timer on the fryer so it starts cooking when you want it to, and it automatically shuts off when the cooking time is done (a great safety feature for chefs who get easily distracted).

Buy it: Amazon

4. Secura Air Fryer; $62


This air fryer from Secura uses a combination of heating techniques—hot air and high-speed air circulation—for fast and easy food prep. And, as one reviewer remarked, with an extra-large 4.2-quart basket “[it’s] good for feeding a crowd, which makes it a great option for large families.” This fryer even comes with a toaster rack and skewers, making it a great addition to a neighborhood barbecue or family glamping trip.

Buy it: Amazon

5. Chefman Turbo Fry; $60


For those of you really looking to cut back, the Chefman Turbo Fry uses 98 percent less oil than traditional fryers, according to the manufacturer. And with its two-in-one tank basket that allows you to cook multiple items at the same time, you can finally stop using so many pots and pans when you’re making dinner.

Buy it: Amazon

6. Ninja Air Fryer; $100


The Ninja Air Fryer is a multipurpose gadget that allows you to do far more than crisp up your favorite foods. This air fryer’s one-touch control panel lets you air fry, roast, reheat, or even dehydrate meats, fruits, and veggies, whether your ingredients are fresh or frozen. And the simple interface means that you're only a couple buttons away from a homemade dinner.

Buy it: Amazon

7. Instant Pot Air Fryer + Electronic Pressure Cooker; $180

Instant Pot/Amazon

Enjoy all the perks of an Instant Pot—the ability to serve as a pressure cooker, slow cooker, yogurt maker, and more—with a lid that turns the whole thing into an air fryer as well. The multi-level fryer basket has a broiling tray to ensure even crisping throughout, and it’s big enough to cook a meal for up to eight. If you’re more into a traditional air fryer, check out Instant Pot’s new Instant Vortex Pro ($140) air fryer, which gives you the ability to bake, proof, toast, and more.

Buy it: Amazon

8. Omorc Habor Air Fryer; $100

Omorc Habor/Amazon

With a 5.8-quart capacity, this air fryer from Omorc Habor is larger than most, giving you the flexibility of cooking dinner for two or a spread for a party. To give you a clearer picture of the size, its square fryer basket, built to maximize cooking capacity, can handle a five-pound chicken (or all the fries you could possibly eat). Plus, with a non-stick coating and dishwasher-safe basket and frying pot, this handy appliance practically cleans itself.

Buy it: Amazon

9. Dash Deluxe Air Fryer; $100


Dash’s air fryer might look retro, but its high-tech cooking ability is anything but. Its generously sized frying basket can fry up to two pounds of French fries or two dozen wings, and its cool touch handle makes it easy (and safe) to use. And if you're still stumped on what to actually cook once you get your Dash fryer, you'll get a free recipe guide in the box filled with tips and tricks to get the most out of your meal.

Buy it: Amazon

10. Bella Air Fryer; $52


This petite air fryer from Bella may be on the smaller side, but it still packs a powerful punch. Its 2.6-quart frying basket makes it an ideal choice for couples or smaller families—all you have to do is set the temperature and timer, and throw your food inside. Once the meal is ready, its indicator light will ding to let you know that it’s time to eat.

Buy it: Amazon

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

Looking to Downsize? You Can Buy a 5-Room DIY Cabin on Amazon for Less Than $33,000

Five rooms of one's own.
Five rooms of one's own.

If you’ve already mastered DIY houses for birds and dogs, maybe it’s time you built one for yourself.

As Simplemost reports, there are a number of house kits that you can order on Amazon, and the Allwood Avalon Cabin Kit is one of the quaintest—and, at $32,990, most affordable—options. The 540-square-foot structure has enough space for a kitchen, a bathroom, a bedroom, and a sitting room—and there’s an additional 218-square-foot loft with the potential to be the coziest reading nook of all time.

You can opt for three larger rooms if you're willing to skip the kitchen and bathroom.Allwood/Amazon

The construction process might not be a great idea for someone who’s never picked up a hammer, but you don’t need an architectural degree to tackle it. Step-by-step instructions and all materials are included, so it’s a little like a high-level IKEA project. According to the Amazon listing, it takes two adults about a week to complete. Since the Nordic wood walls are reinforced with steel rods, the house can withstand winds up to 120 mph, and you can pay an extra $1000 to upgrade from double-glass windows and doors to triple-glass for added fortification.

Sadly, the cool ceiling lamp is not included.Allwood/Amazon

Though everything you need for the shell of the house comes in the kit, you will need to purchase whatever goes inside it: toilet, shower, sink, stove, insulation, and all other furnishings. You can also customize the blueprint to fit your own plans for the space; maybe, for example, you’re going to use the house as a small event venue, and you’d rather have two or three large, airy rooms and no kitchen or bedroom.

Intrigued? Find out more here.

[h/t Simplemost]

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.