The Harvard Business Review has a piece this month on research by Lawrence Frank, Bombardier Chair in Sustainable Transportation at the University of British Columbia, on the effects of cul-de-sacs in neighborhoods in King County, Washington. He found that residents in areas with the most interconnected streets travel 26% fewer miles by automobile than those in areas with many cul-de-sacs. Meanwhile, recent studies by Frank and others show that the higher a neighborhood’s overall walkability, the greater the amount of walking and biking— which means a drop in per capita air pollution, fuel use, and body mass index.
The theory behind cul-de-sacs was that they lessened traffic, since they change the primary function of local streets — rather than offering a way to get anywhere, now they simply provide access to private residences. The problem is that this design inherently encourages car use, even for the shortest trips. It also limits the growth of communities and transportation options. Consider the above maps of one-kilometer walks in two different Seattle suburbs — the first, in Woodinville, is all cul-de-sacs that result in a disconnected jumble of streets with no walking or bike paths, while the second, in Ballard, offers an interconnected network of streets that provide easy access to shopping, parks, and other destinations. The argument that cul-de-sacs increase safety because they limit traffic is also misguided — the more empty and desolate a suburban (and often affluent) street is, the more likely crime is to occur. Also, it’s much harder for emergency vehicles to reach these homes if they’re sequestered in the belly of a web of disconnected dead-ends.
As more and more direct evidence piles up that these dead-end developments are doing no one any good, the cul-de-sac tides are beginning to change: Last year, the Virginia legislature passed a law limiting cul-de-sacs in future developments. And if other states see the benefits for VA – more efficient streets that are cheaper to maintain, as well as other savings from not having to widen arterial roads that otherwise were overburdened by cul-de-sacs — perhaps they’ll follow suit.
Image: Urban Design 4 Health
May 7th, 2010 at 1:29 pm
The graphic says it all. It’s a powerful way to visualize how limiting a planning approach that is cul-de-sac dependent really is.
May 7th, 2010 at 1:44 pm
I’ve been to a couple neighborhoods which use vehicular cul-de-sacs but utilise a ped/bike grid system. That is, while you hit a dead-end in a car; trails & sidewalk keep going. I’d be curious for such a hybrid treatment to be considered among such studies, as well.
May 7th, 2010 at 1:51 pm
The graphic is precious, but I wish you’d quoted research about it by people whose salaries aren’t paid by Bombardier. Frank’s findings may be true, but his conflict of interest is too glaring. There are plenty of researchers making the same arguments who are not paid shills.
May 7th, 2010 at 1:54 pm
I agree with Bossi. In fact I used to live in a condo on a cul-de-sac, but I was able to get access by foot/bicycle to the busy “real street” next to me. It worked perfectly. I walked all the time.
May 7th, 2010 at 2:17 pm
According to my sister, who lives in Ballard:
“These guys need to get their facts straight. Ballard is not a suburb (although it once was a long time ago). Comparing Woodinville to Ballard is basically comparing the suburbs to an in-City high-density residential neighborhood. Ballard is more walkable for a myriad of reasons, few culs-de-sac probably being low on the list. I don’t argue with their point, but come on. Pick better examples!”
May 7th, 2010 at 3:03 pm
mika a,
The problem with this is that there are really very few actual suburbs in the area that have a grid to compare. They all look like Woodinville. The Ballard neighborhood chosen is a residential area, with only the very southern tip (the bottom couple of triangular block sections) having any significant number of non-residential buildings. They deliberately avoided including the parts of Ballard that have been putting in mixed-use density. So despite being in the city proper, this is a good example of an old suburb that represents non-cul de sac neighborhoods quite well.
I’m sure if they could have they would have used an example that didn’t have that tip in the retail part of Ballard. But if you look at a less blurry map of the area, the grid pattern breaks down north of 85th, which was the traditional city limits until the cul de sac era.
May 7th, 2010 at 3:07 pm
So noted, Cascadian, thanks for the response.
May 7th, 2010 at 3:11 pm
I would generally agree with the research. In my opinion cul-de-sacs have been seen as a cure all for suburban traffic problems. Link some cul-de-sacs to a curvy trunk road, and boom, vehicle speeds are down, and you have no four way intersections, but of course it introduces a new set of problems, residents are so nested within the cul-de-sac network they drive everywhere, even in places with footpath linkages from cul-de-sac to cul-de-sac. They partly drive cause it’s too hard / too far / too indirect to walk, and partly because there is no public transport. Either the geometry of the road is a pain for buses, or the route become too long and inefficient.
May 7th, 2010 at 3:43 pm
Cascadian, if there don’t exist gridded suburbs in Vancouver, then the rigorous thing to do is look at a region where they exist. The Northeastern US is teeming with gridded suburbs, enough of which are high-income that it’s possible to control for demographic variables.
May 7th, 2010 at 3:47 pm
I’ve heard many urbanophiles echo Duany’s arguments against suburban street patterns. However, your example features meandering lanes with culs-de-sac forming a vine-like branching pattern that has minimal connectivity and traffic choke points near the trunk. To say that only culs-de-sac are at fault is to blame the lesser of two evils.
Let’s take a regular, rectangular street grid, like the one seen in the right-hand image in this article. If one out of every N intersections (where N >= 4) is replaced with a (T + cul-de-sac) pattern and the (T + cul-de-sac) pattern is distributed regularly and thoughtfully, the neighborhood’s automotive and pedestrian range and connectivity is minimally affected while providing a choice for potential homeowners to live on a block where vehicular through-traffic is reduced. Furthermore, if the cul-de-sac also has a sidewalk that connects through to the T intersection, pedestrian range and connectivity are not affected at all.
I agree the “lost in the twisted ‘burbs” street patterns are wasteful and of low utility. I even know of a neighborhood named Tanglewood (no lie) that I use as a poor example. But to argue for the elimination of culs-de-sac completely is to advocate an authoritarian viewpoint, alienate the preference of some homebuyers and reduce the toolset of the urban designer.
May 7th, 2010 at 4:36 pm
I’m not sure I really believe this. As a kid of the ‘burbs, there were many problems with our isolated subdivision, but kids really could play in the street and have little fear of cars. My street was a through street and we would all often walk over to the nearest cul-de-sac to play ball or let dogs loose.
May 7th, 2010 at 4:52 pm
I thought the death of community was what suburbanites wanted. People who buy in the ‘burbs want a house that is enormous, with plenty of air conditioning, so that when they get home from their long commutes they can lock the doors, close the windows, hang a no solicitation sign out front, grab a beer and forget about all of the debt that they are in, and have high enough fences so that they never have to talk to their neighbors.
Killing community was the point of the ‘burb.
May 7th, 2010 at 5:25 pm
Killing community wasn’t the goal of suburbia, but control (or the illusion thereof) was and is a major draw. Cul-de-sacs give the illusion of control because there’s only one way in, and there’s no real reason for anyone who doesn’t live there to be there.
May 7th, 2010 at 5:42 pm
[...] Harvard Business Review this month has a small piece on how cul-de-sacs are killing your community by interfering with motor- and foot-traffic [...]
May 7th, 2010 at 7:22 pm
Whitney, why would you want kids to play in the street? Wouldn’t a park make more sense? Or wasn’t there a nearby park to which you could safely and conveniently walk or bike to in your neighborhood? Maybe a better-connected, urban-density neighborhood where kids could walk to a park and play in the grass would be a better option than a disconnected and isolated suburban neighborhood where kids have to play on asphalt streets.
May 7th, 2010 at 8:13 pm
What about crime? My perception is that a cul-de-sac is less crime-prone than a through street. I bet I am not alone in that belief. Is it true? I’ll bet someone knows.
What about the risk of poor urban planning? The quiet residential, but through street my parents bought on was allowed to become a major thoroughfare for twenty years before it was fixed. In a cul-de-sac you don’t run the risk that better connected neighbors will arrange to shunt their traffic through your neighborhood.
May 8th, 2010 at 12:39 pm
Please show a topo map of each area. I work in the business park right next to Woodinville map area. To put in grid system would have meant a regrade of the entire area. Not to mention that little bear creek runs right through this area and there are a lot of wetlands.
ANother example of someone not doing their research….
May 8th, 2010 at 1:42 pm
The problem (it appears) with the study is that it doesn’t control for population density. In King County, cul-de-sacs are overwhelmingly located in lower-density areas.
We already know that residents of low-density neighborhoods drive farther — there’s less nearby!
It appears that this study is just substituting “cul-de-sac” for “low density” and “connected streets” for “high density.” It doesn’t tell us anything we didn’t know already.
To make any useful comparisons of street types on driving habits, you’d need to compare through-street neighborhoods with cul-de-sac neighborhoods with matching population density.
I don’t know where you’d find those kinds of matching neighborhoods, but it’s certainly not King County, Washington.
My first thought is Albuquerque or Tucson, which have much more uniform population density than the Seattle area, but still have a wide variation in neighborhood configuration.
May 8th, 2010 at 5:13 pm
Joseph, we played in the streets as kids and want our own to have the same option. Streets are great for cricket and cycling, parks are great for soccer.
May 8th, 2010 at 5:15 pm
Perhaps people in cul-de-sacks have some other socio-economic factors that influence driving?
Families are often attracted to them, because they want to keep young kids safe from speeding drivers.
Don’t people with kids also drive more?
I agree, cul-de-sacks are not fun for pedestrians, walkers and bikers. Then again, neither is 50mph trucks flying up and down residential areas with radios blasting. No municipalities anywhere seem to make an efforts to enforce residential traffic laws.
I’m all for mobile speed and noise enforcement cameras in residential zones; then perhaps we can be done with cul-de-sacs.
May 8th, 2010 at 5:16 pm
Jim, my perception is the opposite of yours - I find streets with no pedestrian or auto traffic sketchy. I don’t know of any research about the actual crime rates, but I’m sure it exists.
The risk of poor urban planning is just a risk that other subdivisions will go for cul-de-sacs. A ban on cul-de-sac development would mitigate that. Even without a ban, there are ways to calm car traffic without closing off the street: narrow driving lanes, tight curve radii, plenty of trees close to the roadway, a roadbed that starts getting bumpy at high traffic speeds.
May 8th, 2010 at 9:14 pm
Actually, the correct plural form of cul-de-sac is culs-de-sac not cul-de-sacs.
May 8th, 2010 at 9:34 pm
I can’t agrue with the facts in his study, but as a parent that raised 2 kids on a cul de sac I loved it and highly recommend it. The street was safe, very little traffic and only residents came through, another huge safety factor. Our cul de sac was off of a through street for the development and we had access to a running/biking path at the end of the street which we used all the time.
I think you can make stats turn out almost anyway you want and the study does not take lifestyle factors into consideration. I would not have traded that lifestyle for our kids for anything. Our community was well planned and we loved it. Sometimes quality of life, safety, and family environment trumps the “numbers”.
One last thing, if you build a development for “maximum efficiency” and people still prefer the privacy of a cul de sac will they buy ugly urbanized developments? By the way, do you have kids? Have you lived in a well planned community with cul de sacs or was this study done from your office?
May 9th, 2010 at 12:59 pm
@ Bill:
Being one of two brothers to grow up in a cul-de-sac, I’ll agree that it has its moments…but that usually applies more to new developments, as that’s where most new families (i.e. with kids) will choose to live. As a kid, it was ok to have a court to play in, but it was always a treat to go to relatives’ houses that were in the vicinity of stores/playgrounds/other streets.
It sounds as if you think the planned cul-de-sac development style is superior for allowing kids to play safely in a family environment, and it is here I must disagree with you. Having lived in West Philadelphia for 5 years, I see that raising children in an urban residential area is just as good, if not better, than the suburbs. With hundreds of diverse (ethnically and socioeconomically) families with young kids within only a few square miles, the environment is perfect. Throw in ubiquitous public transport, dozens of parks, and bike-friendly streets, and you have the perfect cure to the isolated/protected suburban lifestyle.
Not “maximized” efficiency or safety, but optimized in every way possible. And isn’t that what engineering is all about?
P.S. - Pardon my lack of architectural discernment, but how is a cookie-cutter, vinyl-sided suburb less “ugly” than a historic rowhouses on tree-lined streets?
May 9th, 2010 at 1:28 pm
It seems to me that all of you are right.
How so? It seems to me that the cul-de-sacs are a classic example of “individual rationality, collective irrationality.”
From the standpoint of each individual householder, it would be great to have the only cul-de-sac in the neighborhood, for the reasons stated by Mr. Grunau.
But if everyone has one, and every single street is either a high-speed arterial or a cul-de-sac, then you have unwalkable neighborhoods surrounded by high-congestion unwalkable arterials- a result that no one really wants.
The right answer? Balance, balance, balance - either by combining a residential grid with a few cul-de-sacs here and there (as is common in midtown Toronto) or perhaps through a fused grid (www.fusedgrid.ca). If you have to walk through a dozen cul-de-sacs to reach a store, that’s bad. If you have a couple of cul-de-sacs branching off from a basically-gridded street , not so bad.
May 9th, 2010 at 2:22 pm
Bill, have you lived in the Brahmaputra Delta? Perhaps in the LA Basin near a freeway? Or are you just blithely assuming that killing people with pollution for your own personal preference is acceptable behavior?
May 9th, 2010 at 7:01 pm
Comparing two regions using only their road maps, as has been pointed out, is a poor way of determining how easy it is to walk or bicycle through. WRT Crime, I would be interested to see how the proximity to non-residential services or businesses (like grocery stores, malls, movie theatres, etc) affects it.
May 9th, 2010 at 11:52 pm
Okay, let me be less snarky for a moment. I grew up in Tel Aviv’s Old North, where all streets are through-streets, but many are so narrow there’s little point in using them for through-traffic. Check “6 Basel Street, Tel Aviv” on Google Maps. The neighborhood is safe, and unlike your average American suburb, it’s walkable; it’s also dense, at about 15,000/km^2. The neighborhood I currently live in, the Upper East Side, takes it further: it’s on a strict grid, it has 42,000 people per km^2, it’s highly walkable, and its murder rate would put many favored-quarter suburbs to shame. The air pollution on the UES isn’t very good - mostly because of cars driven by suburbanites - but it’s nowhere near as bad as in East Harlem or Los Angeles.
Both North Tel Aviv and the Upper East Side are based on exclusion, possibly to the same extent as the suburbs - though neither neighborhood would take pride in having only residents use its streets. Most residents of both neighborhoods would not take it well if the local low-income minority groups started moving in. Rich communities have no social conscience regardless of their urban form. The difference is that the Old North and the Upper East Side engage in neglect of the poor; they don’t add to the problem by polluting the air, demanding city-bisecting freeways for their convenience, or collecting infrastructure subsidies.
May 10th, 2010 at 9:14 am
[...] Cul-de-Sacs Totally Fail to Deliver Purported Benefits (Infrastructurist) [...]
May 10th, 2010 at 9:19 am
@!!Dean,
You seem to be describing SW Washington DC to a tee… and unfortunately it sucks. Gridded streets in the rest of the city trump this 60’s debacle hands down.
May 10th, 2010 at 9:31 am
[...] Infrastructurist explains: The problem is that this design inherently encourages car use, even for the shortest trips. It also limits the growth of communities and transportation options…The argument that cul-de-sacs increase safety because they limit traffic is also misguided — the more empty and desolate a suburban (and often affluent) street is, the more likely crime is to occur. Also, it’s much harder for emergency vehicles to reach these homes if they’re sequestered in the belly of a web of disconnected dead-ends. [...]
May 10th, 2010 at 9:58 am
I grew up in Ballard. For the most part, we walked everywhere, because my family didn’t have a car until about 1990, when I was ten. We lived on a dead-end street (effectively the same as a culdesac) off 24th Avenue, north of Market Street. We still walked down 24th to the Safeway, and to Market Street to rent videos, shop, etc.
I think it’s somewhat unfair to compare these neighborhoods. The retail and residential density in Ballard (and they’ve chosed the densest parts of Ballard) exceed that of Woodinville by a large margin. I’d really like the researchers to find a non-suburban neighborhood with lots of culdesacs and compare the rates of walking. I suspect the differences is places to walk TO, rather than the shape of the road network.
May 10th, 2010 at 10:00 am
I once served on a planning and zoning board in Connecticut in a town with 4 cul-de-sacs. It was argued that that was four too many. I never fully understood this until I moved to a Northern Virginia cul-de-sac; terrible traffic, difficult emergency access (our street lost two houses to a fire), poor snow plowing, etc. In the blizzard of 2010, we lost electricity for 4 days with no way to get wood, go elsewhere, or even call for help.
Everyone loves the privacy and sense of safety, but I think of all the problems that could be alleviated just by residing on a through-street.
May 10th, 2010 at 10:07 am
Interesting. Although I believe the plural of cul-de-sac is culs-de-sac
May 10th, 2010 at 10:59 am
Are you kidding? I raised 4 kids on a culdesac, and it was great! Have you ever seen a 60′ sidewalk chalk drawing? Instant basketball court? 4 square games? Community picnics? And, believe it or not (since we are in Texas) we even herded some escaped cattle, try doing that on a grid!
Everyone on the CSD looks out for everyone else, you know who is driving around the corner, who belongs and who doesn’t.
So, you can keep the grid in the inner city, I’ll take a suburban cul de sac everytime.
May 10th, 2010 at 11:56 am
[...] Cul-de-Sacs Totally Fail to Deliver Purported Benefits (Infrastructurist) [...]
May 10th, 2010 at 2:39 pm
I did a research thesis looking at opportunistic crime rates in different street configurations, normalized for population density. In the sample set, short-block interconnected grids had less crime than broken, disconnected grids or self-looping grids. Land use also seems to make a difference but was not statistically shown here. http://bit.ly/9z1fut
May 10th, 2010 at 2:53 pm
I avoid telling fellow planners, but I almost brag to everyone else that I live on a cul-de-sac =) I have 3 outside cats, a dog, and a toddler and I don’t have to worry as much about them getting hit by a car. Unless you live in an expensive area you’re going to see interconnected streets to accomodate that income base. We walk and bike regularly… it only take a minute to get to the denser area of town.
May 10th, 2010 at 4:23 pm
This conversation is going in a lot of different directions. Perhaps the best examples were not chosen but there is still some important information to take from this short and brief article. The example on the right demonstrates the overall better circulation of a gridded system. Whether on foot or car, you can go further than in the example to the left.
If you’ve had the opportunity to travel around the country, you may have noticed the different ways grids can be configured. A grid doesn’t just mean equal sized squares over and over. Miami has a system that manages to accommodate busy neighborhood commercial centers and quiet neighborhoods, even gated communities. In other places I’ve seen curvilinear street patterns that offer connectivity by loosely following the grid system. The arguments for cul de sacs as they exist in most places is just not strong enough for me.
May 10th, 2010 at 5:37 pm
Interesting article. I wonder how a neighborhood of cul-de-sac design would compare if the roads were heavily interconnected with bicycle/walking paths.
May 10th, 2010 at 5:43 pm
This really is a fascinating, multifaceted discussion. However, there’s a saying which comes to mind here: “The plural of ‘anecdote’ is not ‘data’.”
May 10th, 2010 at 6:01 pm
I’d love to see some of those cul-de-sacs reconnected with walking and bike paths.
May 10th, 2010 at 6:25 pm
Why would a kid want to play in the street? I used to play in the street because it was right in front of our house, our mom’s could see us and call us in for dinner or chores. We did have a park close by and we did go there, but the street was always there and besides we could use chalk to make just about any kind of play field there.
May 10th, 2010 at 9:07 pm
Thanks to Lydia for providing actual research in this discussion.
May 11th, 2010 at 3:33 am
I think the biggest flaws in this argument are the issues of urban-suburban density and location.
In the example on the right (Ballard), there are probably more than one thousand residents living in tight spacing within 8-12 blocks of useful commercial establishments and possible employers, as well as being within the area of public transit convenient to the very nearby city (which in itself promotes foot and bicycle traffic due to ease and availability of use).
The residents of the cul-de-sac area (Woodinville) are live in much wider spaces, and are probably two miles from a grocery store and more from any retail enterprises or jobs. Note also the proximity of the freeway in the first image, limiting design possibilities, as well as geographical landscape elements that aren’t present in or have been paved over in the gridded city streets.
Consider also the distance of these two examples from their metropolitan city-center. The increase in average daily miles traveled is directly attributable to that single fact alone.
In addition to these issues, did the author do any research at all as to the nature of personal relationships between neighbors in the two areas? What does the author define as “community”? I would venture to guess that while the cul-de-sac area has many small communities of 10-12 households, they are more connected as neighbors than those of the single hundred-plus household community.
And since when is crime more prevalent in affluent suburban communities simply because the streets are empty? This is the opposite of reality. You don’t see bars on the windows and doors of these homes, yet you do in the city.
The author’s arguments in this article are unfortunately severely flawed, owing almost all of his information to correlation rather than causation, and being outright wrong in other respects. Simply being able to travel through an area easily is not a valid argument for residents of a neighborhood. The primary problem with the premise of the article is that the grid neighborhood does not stand up to the change in spacial relationships of a large land-area low-density neighborhood.
And for those commenting who have never lived in a suburban area, there are parks (playgrounds and open lawns, primarily), but they are not the necessary land-use areas as they are in city street neighborhoods. The suburban neighborhood is itself a park, allowing any kind of recreation just about anywhere in its public spaces, due directly to its low traffic flow. This allows children to play much closer to their homes, maintaining safety and connectivity to the community at the same time.
May 11th, 2010 at 6:12 am
Stuff White People Like: Cul-de-sacs
May 11th, 2010 at 6:19 am
I grew up on a cul-de-sac and there was plenty of crime. It wasn’t chaos every day but it’s not like it never happened. I have a very vivid memory of some dude running down the street with a stolen toolbox, and its rightful owner screaming obscenities at him. Hilarious stuff happens in suburbia sometimes.
My mom still lives there and a guy just walked in, ripped out the computer and left. She left the door open so the cat could come in, went to the restroom and when she got back she saw a guy running out of the house with the computer under his arm. Incredibly opportunistic crime!
I’m sure you could get away with that kind of shit easily on a grid configuration, but I buy into the whole concept that people don’t want to commit crimes on a busy street, which is more of less the kind of environment I live in now. My apartment hasn’t been robbed, but my car has. Parking lots are also barren wastelands…
I love anecdotes.
May 11th, 2010 at 12:38 pm
What a bunch of crap. Do you live on a Cul-de-sac? They are so much safer for kids. The families are so much more likely to gather and talk on all sides of the street and in it due to the decreased traffic. Not only that, but it’s like a small village where everyone is able to watch out for everyone else. And due to the shape of the cul-de-sac most of the houses are focused on each other so there are always a few sets of eyes on the street and your house. Come on over to my neighborhood and enjoy the safe street without the traffic that commonly exceeds the speed limit by 20 mph on the main street off our cul-de-sac. We love it and so do our kids. Another example of research without being submerged in your project. Does stated expert live in or on a Cul-de-Sac? Did he knock on any doors to ask people what they thought of livingon a cul-de-sac? Let’s pass a knee jerk law or two based on erroneous internet data that may not apply to all cul-de-sac’s because we’re so informed we can type something into our computer and get back bad data.
May 11th, 2010 at 5:38 pm
“….evidence piles up that these dead-end developments are doing no one any good.”
This isn’t true. I live in a cul-de-sac and the relative quiet and absence of stray traffic is very pleasant. Pleasant has a price tag. What the article talks about are limiting the pleasures of cul-de-sac living to those who can afford expensive homes. Like the automobile, cul-de-sacs are not going away.
Cul-de-sacs, along with freeways, will be rationed to the wealthier few who can afford them. Being in a quiet car is a lot nicer than being in a noisy train or bus, full of smelly, unwashed people. Not having to listen to a loud conversation or one-half of a cell phone conversation is not as nice as privacy. Not having cars speed down our street is, likewise, nicer than the alternative.
Just because most people won’t be able to afford today’s ‘givens’ is no reason to assume the ‘poor’ are idiots. Everyone knows that poorer people get screwed.
May 11th, 2010 at 10:14 pm
I really don’t believe the hybrid solution would work as well as the general grid.
May 12th, 2010 at 12:19 am
It seems, as I read these comments, that most people defend the lifestyle they know. I wonder if they forget the reason for the village that was there before the city grew? Do they live and work within a one mile radius of where they work, shop and play?
I suspect that most of the comments defending the status quo are from people who are totally dependent on cheap energy and believe that everyone should have a car and huge freeways.
May 12th, 2010 at 6:57 am
Living in the city in a grid-system didn’t stop us from playing out in the street. We did it all the time.
As for Bob’s recent comment, I’d like to point out that the trains in DC and Minneapolis are not “full of smelly, unwashed people”, but instead are filled with clean, business professionals…especially at rush hour.
May 12th, 2010 at 2:01 pm
Robert: not everyone. If the smelly, unwashed masses have easy access to houses right next to where proper, cultivated people live, then the world will end.
May 13th, 2010 at 10:07 am
[...] particular, the two areas studied appear to differ on much more than just their street layout. As one commenter [...]
May 14th, 2010 at 8:20 am
[...] How Cul-de-sacs are Killing Your Community – The Infrastructuralist. You know what I hate? Pretty much every neighborhood built after 1980. [...]
May 14th, 2010 at 11:55 am
There are still some things left uncovered here. As a transit planner, I’ve worked in Edmonton, Alberta, which in the late-1970’s did believe in maintaining walk distances to transit stops, whether or not an area had cul-de-sacs. Much of this was accomplished with “U-lots” so labeled on the plans, which were utility corridors that also shortened the runs for utilities into new subdivisions. Children could play in the U-lots and they usually were within view of one to three residences.
We also found that the design of cul-de-sacs and P-loops could be varied to cut walk distances without affecting buyers’ preferences or even the costs to developers (except that they couldn’t save money by using their scale drawing over and over again).
In the Denver metro area, we have all types of street layouts to serve, but the costliest and least productive are areas with cul-de-sacs off of cul-de-sacs, or loops that face away from collector roads. Even if the price of gasoline doubled overnight, these areas would only warrant what they would consider to be mediocre service. Some of these areas are justified by being in the foothills of the Rockies, but some of them appear to have been built on the theory that all the good things mentioned previously could be magnified by designing more complex streets.
The entire discussion about how safe and quiet cul-de-sacs are is offset by the volume of traffic converging on the stem of these neighborhoods out onto collectors or arterials. At 7:10 a.m., there is noticeable traffic stacking up, idling, to get out onto the (unsignalized) road. Late at night, motorists headed to the elite inner cul-de-sacs can take the big curves at the entrances at higher speeds than they can when the shortcut through my inner city neighborhood grid.
Any form of street pattern carried to extremes will create problems.
May 15th, 2010 at 10:24 am
It may be true as far as transportation and conserving energy is concerned. But, safety is very important. I live in a neighborhood that has mostly straight roads and with people driving at crazy sppeds, it is so dangerous to let kids to play in the front yards. I have always envied houses on cul-de-sacs with kids playing basketball, bikes, etc. safely…
May 15th, 2010 at 9:52 pm
One key reason that there are so many culs de sac is that they’re cheaper and easier to build than connective streets, and consume less land. This is especially true if a new subdivision is developed on a small parcel. Look at a map of a typical cul de sac subdivision: the lot depths are the same as those in gridded neighborhoods, and the street system is essentially a grid with all of the nonessential links removed so that houses can be built on the land instead.
A cul de sac layout maximizes profit for the developer, and that’s why it’s so prevalent.
May 16th, 2010 at 6:29 pm
The Cul-de Sacs in my area are kind of getting out of control in Virginia such as there is this one new nighborhood they are putting in with $500,000 houses. There are only two openings in it that are four lanes wide and you simply can’t drive stright down it instead you will have a street go for a 100 feet dead end then have a Cul de Sac break off of it and to add to the mayhem of it all the streets have the same name only with the last name street drive or view.
There was a lovely town in Pennsyvinia called Carlise Pennsyvinia it wasn’t a dense city and the houses where more farther spaced then in some of these modern cookie cutter cul de sac subdivisons. It was a classic grid shaped town where it had an old small local train station in the center of it but everything was linked up by a massive grid of old sidewalks that where in great shape. You walk though this place and go at least two or three miles one way on the sidewalks along nice tree lined streets that didn’t dead end and the traffic was kept undercontrol. This place would make a great example of what the future should be about not this souless sprawl of Cul De Sacs dumping traffic on to monster four and six lane wide highways. Carlise’s street grid was very nice and many of the sidewalks had date markers on them from the 1950’s and 1940’s but they where in good shape and the street trees where at least 50 to 80 years old covering up the sun from hitting the cement. I think there needs to be more places like this vs more Cul de Sacs. What I liked about the place is that you didn’t need to drive around and get into a car and go park it and sit at all the traffic lights and compet with hords of fat cell phone trolls driving SUV’s.
May 17th, 2010 at 8:15 pm
[...] How Cul-de-Sacs Are Killing Your Community. [...]
May 18th, 2010 at 2:35 am
A major flaw in this study that no one yet has pointed out is that correlation (grid pattern and fewer vehicle miles traveled) does not equal causation (grid pattern produces fewer vehicle miles traveled). Is it not possible that people who prefer to drive less end up in gridded neighborhoods, and people who prefer to drive more choose to live in cul-de-sacs? In other words, people being observed may self-select into these different neighborhoods.
May 21st, 2010 at 12:05 am
It might be like a Cul De sacs are a mononpoly in that you try to move it a place do to a job opening but you want to movie into a grid neighborhood with grid streets and sidewalks but the only places out there to buy are Cul De sacs. So even though you want to live in a grid street the only thing there is Cul De sacs so the cul de sac has a monopoly.
May 21st, 2010 at 9:07 am
On the other hand, people generally prefer to live in cul-de-sacs vs. on thru streets. If the motive behind city planning is a higher population density perhaps cul-de-sacs don’t make sense. But if neighborhood desirability is a major factor maybe they do.
May 21st, 2010 at 9:31 am
Jbemory, do you like on a street grid? How do you know a cul-de-sac is soooo much safer?
I grew up in a small, pre-WWII town outside of Pittsburgh. The town was on a grid. We had an alleyway that we would play in without having to play in tons of traffic on the front streets. Everyone knows each other. We basically had all the perks described about cul-de-sacs while being able to walk and bike all over more easily. (also women could walk around town for exercize and all, or people would jog or watever - another pair of eyes that would be lacking on a cul-de-sac. Just sayin.)
May 21st, 2010 at 9:35 am
And don’t forget that these neighborhoods need to cater to more than just children - being in a more dense and walkable town gave us a lot of options for things to do neraby but away from home during our teen years, and allowed for bus service as well. All without having to ask someone’s mum to drive us and pick us up.
May 21st, 2010 at 10:57 am
I agree that a good solution is a (more or less) grid of streets with are cyclable in all directions but no through traffic is possible for cars.
May 22nd, 2010 at 6:11 pm
At risk of playing devil’s advocate, is the non-walkability really inherent to the cul-de-sac system? Why couldn’t a developer combine the cul-de-sacs with trails providing shortcuts to pedestrians and bicyclists?
May 23rd, 2010 at 1:37 pm
Cul-de-sacs are also energy-inefficient. You more often than not have to travel 1-2 kms in the wrong direction — at both ends of each direction of travel — just to reach the arterials.
They also create disorientation for those who are ‘visitors’ and can’t cope with the deviations from right-angle grid patterns.
But they serve a good purpose: cutting down on through traffic by cars and trucks. But they do this by pretty much eliminating traffic of a lighter nature: walking, cycling, roller-blading, boarding, which are not undesirable.
The way to bring back the grid without getting the motor traffic back is to borrow the idea of Duany, et. al.: ‘yield streets. These put two-way traffic on streets that are only wide enough for one-way traffic (usually by allowing parking on both sides or regular streets, or being built from day-one as a narrow street). In this system, motorists have to slow down to pass each other or to pass cyclists, or even to have to turn into a laneway or parking spot to allow the motorist from the other direction to pass. But cyclists don’t have to do this, since they are narrower. This slows the traffic enough to make it safer, and to discourage use of motor vehicles there at all. Slower traffic allows the human-powered travelers to mix with motorists, rather than be relegated to the gutters.
Ottawa, Canada
May 24th, 2010 at 12:06 am
I had no idea that so much could be said on the topic. wow.
May 25th, 2010 at 4:02 pm
I noice with the Cul De sacs is that if the main road leading out of the place is blocked by a acident or something your day is shot. In that it’s the only way out and no way around it. But if you have a grid you can easly go around it. It is easier to go around something in the City of Richomd then it is the suburbs.
May 26th, 2010 at 12:59 pm
I live on a cul-de-sac and I am spoiled by it. I can sit at the edge of the circle to warn about incoming cars, etc. and my small kids can ride their bikes, etc without the fear of getting run over. I can’t imagine moving to a through-street until my kids are older.
May 27th, 2010 at 10:37 pm
I hear again and again how great culs-de-sac are “for the kids.” I never hear about how great they are for the grown-ups. Maybe they’re just great for people who never did grow up, or maybe they’re great at keeping people trapped in childhood.
I would go out of my freaking mind if I had to live in a cul-de-sac. I’d feel like I was in a cage. I want to live in a community, not a Habitrail, where the tubes dictate where I get to go.
And I don’t want my kids growing up without developing some alertness to risks in their environment. I want them to know, both consciously and subconsciously, that traffic comes from more than one direction, and that strangers are normal.
May 29th, 2010 at 3:10 pm
[...] Found this here: [...]
June 1st, 2010 at 4:15 pm
Ballard? Isn’t Ballart part of the city of the Seattle? Since when was it a suburb?
June 1st, 2010 at 8:17 pm
The benefits and drawbacks of cul-de-sacs depend on what your view of an ideal community is. There are good, in my view, arguments for and against them and what a larger community’s over-all planning goals are determine whether or not cul-de-sacs should be permitted. Cul-de-sacs actually are a little community in and of themselves. Neighbors living in the sac are more likely to interact that those living on straight line streets. What has led to the death of sense of community are the 2 garages (storage sheds) and 2 car parking lots built on the front of houses and the lack of front porches as a result. Porches are community meeting places. Do you ever see anyone in our modern burbs sitting on a front-of-the-house porch? People stay inside and out of sight because they don’t have a porch to sit on to watch their kids play or people walking around.
Another killer is the development of 4 lane interstate highways that led to the development of 6 and 8 lane interstate highways making it possible for people to live further and further from the city core. People who live 45 minute drives to and from their workplace have no time to socialize with their neighbors.
I think the model for urban development is found in the cities in Europe. There are no interstate highway systems that serve as conduits for commuters in and out of the city. There is no parking or parking is outrageously high. Severely limit those two things, multi-lane highways and cheap, accessible parking, and the cities fill up again and urban transportation will flourish.
June 5th, 2010 at 3:01 am
I live near Berkeley where they have replaced cul-de-sacs with “traffic calming” This is where they plant a big tree or stick a permanent barricade smack in the middle of residential intersections so cars can’t go through. The first time one tries to cut through a neighborhood there’s a good chance they’ll hit one of these intersections and get dumped back onto the nearest through street. Several reasons this works better than cul-de-sacs:
*Cars can still go left or right so it’s not (usually) a dead end
*bikes and pedestrians can still go through just fine
*takes up less space and doesn’t require the road to be rebuilt
I hated the traffic calming at first but after a while you just get used to driving on the through streets rather than trying to cut through people’s neighborhoods. And it is true that I’ve seen people hold street parties with BBQ and kids running around right in the middle of the road in Berkeley, which wouldn’t be possible without traffic calming. That being said, now that I’m used to the way they do it here cul-de-sacs drive me insane. So often they are part of a ridiculous system of winding roads that doesn’t go anywhere…once parked my car on the wrong cul-de-sac in LA and it took me over an hour to get back to it! When you think about it, every street doesn’t need to be a dead end to reduce through-traffic, just enough twists that it’s more convenient to go three blocks out-of-the-way to the street that’s designed for traffic. It works for us in California!
June 7th, 2010 at 9:46 am
it is not about cul-de-sacs, it is all about design. don’t be a fool. grid system just for robots
June 22nd, 2010 at 8:31 am
[...] grid (and its political effects) before. Other reactions on the walkshed study are available at Infrastructurist and Human [...]
June 23rd, 2010 at 12:31 pm
If cul-de-sacs cut down on infrastructure that needs maintenance, then they can be a good thing.
June 23rd, 2010 at 12:32 pm
[...] Unintended Consequences of Cul-de-sacs [Harvard Business Review] The Cul-de-Sac Ban [NYT Magazine] How Cul-de-Sacs Are Killing Your Community [Infastructurist] The Damaging Effect of Cul-de-sacs on Walkability [Seattle Transit Blog] Is the [...]
June 26th, 2010 at 4:17 pm
I used to deliver for King Soopers (until I broke my hand) & I can say from personal experience that Cul-de-sacs are a pain in the butt! One community builder thought it would be “cute” to have one in the shape of an “H”. Only 1 way in & out is via the the crossbar. The streets also have the same name & no differences i.e. E Cherry & W Cherry; but 1 street called Cherry. The only difference was in the minds of the residents.
July 16th, 2010 at 4:52 pm
I grew up on an anti cul-de-sac and moved with my family to a cul-de-sac in HS (and have lived in cities whenever I chose for myself), and it’s now in hindsight that I can look back and see the planning failure of a cul-de-sac.
In general, most houses in a new subdivision lie on the feeder streets while a select few get to be on the coveted cul-de-sac. Compared to the street I grew up on this is completely inefficient.
The “anti cul-de-sac” I grew up on was part of a fantastic residential grid of streets. The main streets had larger houses and deeper setbacks, while the bulk of the housing sat on cross streets with smaller setbacks. Most only went for three or four blocks so there was no end destination making them like a cul-de-sac in their traffic patterns. The upside was that each block had 30-40 houses with 2-3 larger houses on the “end cap” of the block. We frequently played in the streets since few non residents drove down the streets and those that did knew to drive slowly. Instead of riding my bike in circles on a cul-de-sac I had nearly a quarter mile to ride back and forth. Because it was part of the grid and not an isolated development there were also regular walkers from nearby blocks and was able to walk to school and nearby parks (and ride my bike to stores before I was technically allowed to).
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=10606&sll=37.0625,-95.677068&sspn=37.871902,78.837891&ie=UTF8&hq=&hnear=White+Plains,+Westchester,+New+York+10606&ll=41.010313,-73.765469&spn=0.008825,0.019248&t=h&z=16
July 20th, 2010 at 4:42 am
There has also been interesting research on whether crime increases or falls in cul de sac compared with interlinked streets Colin Buchanan’s blog looks at this
http://colinbuchanan.wordpress.com/2010/04/13/is-there-a-link-between-design-and-crime/
August 3rd, 2010 at 10:19 am
Culs-de-sac don’t necessarily have to promote car use - after all, in a high density, mixed use context, with pedestrian walkways between culs-de-sacs, or even in a suburban context with park-and-rides along the arterials, the result can be considerably friendlier to transit, by causing the collection of people and traffic in one or more locations. This result presumably works best with a concentrated CBD area, unless someone comes up with a way to solve the “last mile” problem of transit access to distributed workplaces. The problem is that culs-de-sac are deployed in a random, dispersed fashion with low density, single-land-use characteristics, resulting in a situation unfriendly to transit and walking and pretty confusing to drive.
August 3rd, 2010 at 10:43 am
For the record, I grew up in quarter-acre-lot land, but not on a cul de sac. My neighborhood is mostly interconnected streets, although there is a cul-de-sac on one end of it and there are also some dead-end streets. There is a shopping center within walking distance, but the stores amount to bodegas and small shops, and it’s a small shopping center.
It has an unusual history for a suburban area, though, having been started by bodybuilders, expanded into a vacation cabin area, and then fleshed out into a full suburb with the houses that come along with it.
August 12th, 2010 at 10:38 am
[...] with cul-de-sacs. For the love of infrastructure, I strongly encourage everyone to advocate for attractive, [...]
August 18th, 2010 at 11:17 am
The plural of cul-de-sac is culs-de-sac, not cul-de-sacs. One would think the Harvard Business Review would know that.
August 25th, 2010 at 12:35 pm
sounds like its a matter of choice.
live where you want to and don’t live where you don’t.
obliviously money is ALWAYS the issue.
August 27th, 2010 at 11:37 am
[...] in fact be safer than cul-de-sacs. Reporting on the same research by Frank, Melissa Lafsky adds inThe Infrastructurist, “the theory behind cul-de-sacs was that they lessened traffic, since they change the primary [...]