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One of the reasons many people LIKE cul-de-sacs is NIMBYism on a small scale: They want to avoid cut-through traffic, and living on a dead end street is a great way to do that. And pardon me for painting with a broad brush, but such NIMBYism is not uncommon in Lake Oswego (a wealthy inner-ring Portland suburb for those not familiar with the Portland metro area).

And from the point of view of developers, a network of dead-end streets is the most optimal layout for a subdivision. Any redundancy in the street network means additional square feet (or meters) which cannot be sold to homeowners.

To add insult to injury, normally homeowners on the lakefront side of the street could have escaped in their boats--the lake is navigable to small craft, and most property owners on the lake have boats moored there. But at the present time, the lake has been drawn down for various maintenance reasons, and until next spring, when the work is done and the lake is allowed to refill (it is fed by a canal which is presently closed), these homeowners' backyards abut to a big pool of quicksand.


On a serious note, what if someone had a medical emergency?

I'm surprised given the myriad of codes and regulations dictating (perceived) safety standards that municipalities, civil engineers, etc. would actually BAN cul-de-sacs for this very reason.

Won't someone think of the children!?

In very rare circumstances are cul-de-sacs needed as the only option for development. Such as running into a large hill.


two modes of transport?

BOATS! look how close they are to that water


Poetic justice.


I was under the impression that insurance costs more when you're on a cul-de-sac due to the increased difficulty of emergency services access. If that's true, then people who choose that lifestyle are literally paying more for it.


I believe there are laws in California that require two access points for fire engines in neighborhoods. So you're allowed to have something like a 6 house cul-de-sac but not a 30 house one. So on that map, something like a slightly shorter Ash street would be legal, but not lake front.

Dexter Wong

Reminds me of a situation on Oahu where a tree fell on the only road leading into Pacific Palisades (a neighborhood above Pearl City) and residents were trapped in the sense that no one could drive in or out until the tree was removed.

jim karlock

On the other hand cul-de-sac have a much lower crime rate due to the lack of strangers - any strangers stand out.
Steven Town, architectural liaison officer at the West Yorkshire Police disused this when he was in Portland a few years back:


and again in Minneapolis, MN




Yeah you're right Jim, Orenco Station is just festering with crime. /sarcasm

Those architects thought they were putting in nice tree-lined connected streets, little did they know they gave the opportunity for rapists and murderers to walk along them.

Get a life, man.

Peter VE

Engineer Scotty: by limiting the entry to a single point, the traffic load on the single point will be larger, with the consequence that "connector road" will need to be bigger, and those desiring to go west will spend more time to get there. Of course, these costs are shifted from the developer to the taxpayers and homeowners. On Lakeview, if there's a high school student in the house, they would need to bike on Stafford to get to the high school (unless they are gifted with a car.) Stafford looks really dangerous from a bicyclist's view. If our hypothetical student could get out the other end, they would have a network of back roads to get to school. If our hypothetical family were members of the United Methodist church, they could walk to church Sundays instead of driving. If.... but you get the point.

jim karlock

ws: Get a life, man.
JK: Got any evidence to back up your position? I got my information for one of Europe's leading experts on the subject. (He wrote the book!)


Alon Levy

Jim, there was work done a few months ago at UT Austin showing the opposite: controlling for income, more connected neighborhoods in Austin have lower crime rates. Eyes on the street work much better than gang-style turf marking.

The eyes-on-the-street effect has also been observed in Suginami, Tokyo, where a flower planting program, intended to make residents spend more time watching the streets, caused the burglary rate to go down 80% in five years.


Well, in this case, it looks like there is a ravine at the end of the street. I would much rather they end the street there rather than fill in the ravine and culvert the stream like was done for most of Vancouver and countless other cities around the world.

If emergency access is required for a once in several decades problem like a tree falling down on the road, they could always build pedestrian/cyclists paths or bridges that are wide enough for emergency vehicles. This also makes cycling and walking much shorter than driving for some trips which is really what we want.

The grid is OK for flat land without any natural features but hopefully we are past the era of bulldozing down hills to fill in ravines to impose the mundane order of the grid on the landscape. An unconstrained grid with motor vehicle access everywhere, by the way, is the least land efficient way to organize local access. Surely we can do better than that while still allowing for efficient bicycle and pedestrian access.


I recall a story from a survivor of the 2009 Black Saturday bushfires. The guy had been visited months earlier by the local fire authority as part of their fire education program. They told him if it came to a fire, they wouldn't be coming up his street to protect his house because he was in a cul-de-sac. He said it was this that made him decide on the day to just evacuate early. His house was destroyed in the fire.

I know this is an extreme example. I'm just trying to keep fear alive.

Ben Smith

Mentioned this in another cul-du-sac thread, but the one I live in at least has a number of pathways which cut through the garden like road network. This helps to make walking somewhat more manageable, and makes cycling very competitive with driving.

Peter S.

"Dead worm suburbs" is the best moniker I've heard for snaking cul-de-sac development.

I can't remember who the presenter was at the NZ Walking Conference a couple years back. I think she was originally Aussie, but was working for the City of Manukau. Anyway, since that time I've been working to spread this term.



Connected streets are better from the point of view of access, both transit and emergency. As discussed above, there's some evidence that they also improve community cohesion. It's worth noting that 'connectivity,' or the lack thereof in this context is meant in a vehicular context - cul-de-sac's usually, or at least should have, multiple pedestrian and bicycle access points.

However, vehicular connectivity encourages cars, and through travel by cars, which can often drive fast. This can be dangerous, and damage the use of the street as a social space. Particularly with the introduction of sat-nav, some back-street routes can't rely on secrecy to protect them from that any-more.

In the UK, some formerly connected streets have given up and become vehicular cul-de-sacs by installing bollards. In cases where this interferes significantly with bus routes, automatic retractable bollards have been installed, which seems a good solution. Lowering speed limits is another.





@dorkmo, who wrote, "BOATS! look how close they are to that water."

Aside from being drawn down at the moment, as mentioned by EngineerScotty, a curious fact about the body of water called Lake Oswego is that despite being factually navigable per historic practice, US Coast Guard determination, and every real estate advertisement for waterfront property there, it was especially declared non-navigable by the US Congress in 1976, under the good auspices of former Senator Hatfield. This is important because, in Oregon, all navigable waters are publicly owned, along with submerged or submersible parts of their adjoining banks. If Lake Oswego were acknowledged as navigable, then any riff raff could use it. As it is, the entire lake is owned by the private Lake Oswego Corporation and available only to its members, less than 10% of the Lake Oswego population. In fact, at the downtown waterfront they have posted signs, warning the unwary not to dip their toes in the oh-so-private waters.

The moral to me is that those who have enough money and connections to attract the friendly ear of a US Senator find it unthinkable to share space - any space - with anyone even slightly less rich and powerful. This is the same reason there will never be a light rail line through the area, and presumably why the cul de sac such in question was built in the way it was. The slightly less rich then do the same thing, and it's soon turtles all the way down as the saying goes.



jim karlock

Alon Levy: Jim, there was work done a few months ago at UT Austin showing the opposite: controlling for income, more connected neighborhoods in Austin have lower crime rates. Eyes on the street work much better than gang-style turf marking.
JK: Citation please.


Alon Levy

I got the time wrong - it was posted on the Infrastructurist a few months ago, but is actually from 2004. Sorry.

It's here.

Martin ,ACT

I think you should look at what Holland has done before you bag cul-de-sacs or no through streets. Most of the residential streets in Holland have become no through streets for cars ,but Pedestrians and cyclists can go through though. Holland also has the safest roads in the world and the US is well behind in the statistic. Many of Canberra streets were built like this with footpath access beyond the end of the streets though not all cul-de-sacs.
Many of the newly planned suburbs in Canberra work on the grid plan but that only encourages more people to walk if there is right of way to pedestrians and cyclists and the traffic speeds are low 30 km/h(20 miles) or less. If you design a neighbourhood for 50km/h most people will drive no matter how close to services they are.

Houten in the netherlands is a good in example of what cane be achieved with cycle networks and transit with to low /moderate density.

jim karlock

Alon Levy: I got the time wrong - it was posted on the Infrastructurist a few months ago, but is actually from 2004. Sorry.

It's here.
JK: On which of the almost 100 pages? Please provide a quote or two that proves your point.


Craig B

I actually drove election canvassers around in this neighborhood on the morning that this tree fell--they had cleared it up by the time we arrived, though some TV crews were still around filming the aftermath of the tree. I had to drive a 15-passenger van down this street to drop my canvasser off, rather than drop him at the more convenient arterial (which would have made him walk all the way down and then back). Turning around in a 15-passenger van on a street like this was quite the feat...I feel for firefighters.

Canvassing is a great way to experience America's problems with layout, particularly in the suburbs. Just compare how quickly you can knock on 50 doors in a gridded area as opposed to an area like this, full of loops and lollipops.

Incidentally, to dorkmo, who pointed out that people should be able to escape by water--during this month, Oswego Lake has been drained for sewer repairs (the sewers run below the lake, which while natural is now controlled by an outlet dam).

Thanks for highlighting this, Jared! Love the work you do.


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