Understanding Street Capacity

Below is a series of pictures that I just love. I think they do an excellent job illustrating the concept of street capacity, making clear how much valuable urban street space is wasted by private automobile travel.
This first picture above shows 24 cars on a block in some town. It’s amazing how much space is taken up just so a couple dozen people can move around (or store their vehicles if the outside columns of cars are “parked” in this picture).

The second picture below clearly shows how much street space is wasted by all these private, single- occupant vehicles.

The third picture below clearly shows how much street space is preserved when mass transportation such as streetcars or buses are used to transport the same number of people through uniform space.

The last picture below illustrates just how small a space is used by the same number of people when they are pedestrians.
All of these pictures help us to see the intrinsic link between land use (e.g. density, urban design, parking requirements, etc) and transportation. In turn, it helps us understand how high quality urban land uses that emphasize density, pedestrian-oriented design, and transit instead of automobiles actually make for more sustainable environments than less dense or more sprawling locales which facilitate private automobile usage.

When you can to begin to grasp this concept, you will have begun to understand how unsustainable the auto-centric city is even with an unlimited supply of the cleanest, greenest fuel technology.

Photos courtesy of terrian.org and streetsblog.com

6 Responses to “Understanding Street Capacity”

  1. 1 Li'l Pony

    Those photos are really great but I can’t find either of the websites that they are from!

  2. 2 Ryan

    Li’l pony, the website with the pictures illustrating street capacity is http://www.terrain.org/articles/17/rue.htm

    The very top picture of a street in Hong Kong is from streetsblog.com, a great livable cities blog out of New York. I think the streetsblog server is currently down for some reason.

    Hope this helps.

  3. 3 Anonymous

    Actually, car-centric living works quite well in places with lots of space that were designed from the ground up to accommodate drivers. Plano, Texas is a great example. “Everything” is at least a mile away from wherever you are, but getting there only takes 2 or 3 minutes. The great evil in car-land is “Medium-density”… the point where there are too many people competing for too little road space, but not enough density to make subways viable. Cities like Miami are obviously space-constrained.

    The main problem with pedestrian-centric design in Florida is the fact that our climate utterly sucks. It rains daily for 1/3 of the year, and it’s miserably hot & humid for all but a wonderful week or two between December and March. It’s the reason why Dadeland Mall is booming, and Sunset Place is a ghost town (especially during the summer… unlike the Falls, Sunset Place has few covered walkways to protect shoppers during endless summer downpours). In an ideal universe, downtown Miami could be rebuilt from scratch so the bottom 50 feet of every building were for parking, sitting below a sidewalk stretching the street’s width with glass roof above and air conditioning (where the pedestrian entrances would be) that had the general look & feel of a mall. Unfortunately, that’s never going to happen anywhere (besides maybe China, since they literally ARE building brand new CBDs from scratch, all at once).

  4. 4 Anonymous

    car centric living “works well” in terms of vehicle flow in places like the one quoted in texas, yet is unsustainable in the long run. the consumption of land that could have other uses (farms, parks, etc), the amount of gas that is consumed by vehicles (the need to rely on foreign oil), the impact in health of residents, the considerably higher cost of infrastructure per capita are negative factors.

    Few places have an unlimited supply of land, and when it starts getting scarce is when car centric doesn’t work so good anymore.

    Most car-centric places “worked well” when they started being built, like the area in northern florida that was discussed in a recent post.

    Another factor that is not discussed that often enough about car centric cities is the exclusion of society that non drivers suffer in such cities. Teenagers, the elderly, the poor, the permanently and temporarily disabled have a much harder time in car centric cities. The practically become excluded from society, they lose independence since they have no other way of moving and getting access to jobs than relying on often inefficient public transportation.

  5. 5 Ryan

    Anon #1, I tend to disagree with a few of your points. First of all, any city that is designed from the ground up for cars is an example of very poor urban planning, regardless of whether or not traffic flow is smooth. Anon #2 touched on a few points of why this is, but these cities are especially unsustainable.

    I also disagree in part regarding how Florida’s climate dictates levels of pedestrian activity. The main reason levels of pedestrian activity are so low in Florida is because the vast majority of cities and neighborhoods are auto-centric. These places have been built to accommodate vehicles and not humans. These places are fundamentally hostile to pedestrians.

    The rain is almost irrelevant because throughout the state there are many more sunny days. Even during days of rain, it usually is from brief thunderstorms that do not last long. I’ve never had a problem, I just use an umbrella.

    The heat and humidity sucks for a fair portion of the year, but it could be largely mitigated by good urban design and a more comprehensive tree canopy along sidewalks. When you’re out exploring, check out the streets that have these characteristics - they usually will have higher numbers of pedestrians on them than other streets.

    Also, if all of the buildings in our environment had 50 feet of parking at the bottom, it would be a total urban planning disaster. Not only would this encourage people to drive everywhere, it would completely destroy urban design qualities that are critical to a strong pedestrian realm.

    I agree with you to a large extent regarding the medium density in car-oriented cities, though. This is what I am trying to hammer through here in Miami - becoming denser is great and everything, but without quality urban design, pedestrian-oriented infrastructure, and transit accompanying it, you have completely unlivable cities. Miami can’t make up its mind - it wants to become denser and more pedestrian oriented while still catering to the private automobile, which just doesn’t work.

  6. 6 Anonymous


    Plano, TX and Weston, FL are my 2 favorite examples of places that are some of the most horribly designed in the entire country. And talk about a boring place to grow up! I would have long since slit my wrists or committed suicide in some other way if I had grown up as a kid in a place like that. It’s no wonder all the 20 somethings are wanting to move back into the urban core, it’s probably a reaction to being forced to grow up in suburbia. I can’t understand how so many generations of people actually enjoy living in a place like that.

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