Best cul-de-sac design

[Streck]

Prairiesheep,

Thank you. I had hoped to find an international sign that showed a figure almost like a question mark, with an arrow head at the end pointing back at you. This would be perfect for right hand traffic. Perhaps a mirror image for left hand traffic.

Of course I guess we could make one up. I wonder what the process is to get a sign recognized by the international community.

Preferrably the sign would be in a blue diamond field with a white directional arrow. Or would it be a yellow warning sign because of the potentially tight turn around? (Of course, no tandum trucks.)

I did not see a U-turn sign, although I think there are such animals. Maybe that would work.

Preferrably the sign would be self explanatory with no lettering (cul-de-sac is so long at 10 characters).

[mazlin]

You're still preferring Cul-De-Sacs in Sprawl... I want to know how Cul-De-Sacs can be used in urban areas... Sprawl is going to stop in the coming decades, and hopefully Americans will wise up and stop buying crap in sprawl...
Again I ask you, how can Cul-De-Sacs be used in urban areas? (NOT IN SPRAWL). The best Cul-De-Sac designs do not promote sprawl or any development under about 8 units/acre.

In Malaysia cul-de-sacs are rare but popular. But with per capita income a quarter of that in the US, only the rich can afford to live in single-family houses or 'bungalows' as we call them here. How can the cul-de-sac be made affordable for more people?

First, we improve the cul-de-sac by making it bigger to be able to fit in a public green area in the middle because local planning regulations require 10% of any residential development to be open space. Then we create an interlocking arrangement of cul-de-sacs such that each building lot would face at least two cul-de-sacs. If the buildings in this layout were detached houses, they would be in the top range of the market. But here, we sub-divide the buildings into 2, 3, 4 or 6, to create duplex, triplex, quadruplex or sextuplex units.



As we divide the buildings, the land area and the built-up area become smaller; the number of units in the layout and the density of the development go up. Using these multi-family units, each with their own car access, and keeping to Malaysian planning rules, we can get densities up to 12 to 14 units an acre, compared to 4-5 units an acre with the typical 60'x100' detached house layout. This is equivalent to the density of the conventional 20'x70' terrace or row houses.



This is a schematic of a block of 252 houses on 15.6 acres. Note the green area in the middle that links the cul-de-sacs.

[Monamogolo]

Mazlin,
that's really clever! Reminds me of complicated geometry puzzles.
Have you built many of these areas? And has anyone surveyed the residents to get their opinion after living there for a while? Is there much turn-over among residents - is this a stop-over for people on the way up to larger more traditional areas.
How complicated are the utility networks - electricity, gas (if you have it), water and sewerage? How do the garbage collectors like it - seems they have to do a lot of driving to pick up th waste. What's the infrstructure cost per unit or acre compared to the usual grid layouts?

[CJC]

That is really bizarre looking, but quite interesting How do you connect the border areas? Multiple hexagons?

[mazlin]

Have you built many of these areas? And has anyone surveyed the residents to get their opinion after living there for a while? Is there much turn-over among residents - is this a stop-over for people on the way up to larger more traditional areas.
How complicated are the utility networks - electricity, gas (if you have it), water and sewerage? How do the garbage collectors like it - seems they have to do a lot of driving to pick up th waste. What's the infrastructure cost per unit or acre compared to the usual grid layouts?

No project like kind has been built yet. The work is just coming out from theory to practice. One project that has received planning approval is in Kuantan, Malaysia. The site is at the city limits next to a new township. The existing houses are all rows of terrace houses, like these:


The Malaysian grid is maybe not as attractive as the Neo traditional grid housing in the US. That is because single family homes or detached houses are too expensive for almost everyone. Terrace houses cost mainly between USD 35,000 to USD 100,000, but anything above USD 70,000 is considered high end.
An early design that we have for this project is here:



Although there are no residents yet to survey, consumer preference surveys have been done where potential buyers are shown plans or models of the new housing forms and the equivalent conventional terrace houses. The results have been overwhelmingly positive for the new cul-de-sac designs.
One advantage of the cul-de-sac is that you end up with fewer roads. In this case we used 35% of the total development land compared with the normal 40 to 45%. The drains and sewer lines are therefore also shorter; they are less complicated as you might imagine. A detailed study at another project showed 6% reduction in cost.
The cul-de-sacs are about 110' or 34m across, and fire and garbage trucks can circle them.

You can see more about the surveys at: http://tessellarsurveys.blogspot.com/"]http://tessellarsurveys.blogspot.com/
and the study on the comparative cost of the infrastructure can be downloaded here:
http://tessellar.googlegroups.com/web/20060410SavingLand%26InfrastructureCosts.pdf?gda=HFKwml0AAABwYIsq-wPzFzyFDu3WJVLnkjxUZO0txmcrFGkLem6VfGG1qiJ7UbTIup-M2XPURDRyUDIpfGaj_E9tyLrbuJO1mW5Y8ds08_JdRJcnzR3uTj0sxl1eemVHoBZ76Q1Afvs&hl=en"]http://tessellar.googlegroups.com/web/20060410SavingLand%26InfrastructureCosts.pdf?gda=HFKwml0AAABwYIsq-wPzFzyFDu3WJVLnkjxUZO0txmcrFGkLem6VfGG1qiJ7UbTIup-M2XPURDRyUDIpfGaj_E9tyLrbuJO1mW5Y8ds08_JdRJcnzR3uTj0sxl1eemVHoBZ76Q1Afvs&hl=en

How do you connect the border areas? Multiple hexagons?

As you can see from the plan above, the multiple haxagons are seperated by distribution roads; the schematic layout gets adjusted at the boundaries.

[Streck]

Very inovative plan Mazlin!

Where do visitors park?

[mazlin]

First I'd like to apologize for the extra-wide format in my last post. But I don't know how to delete the extremely long link at the bottom. If possible I'd like that line deleted.

Casual parking

In each house, two cars can park side by side. For casual visitors 9 parking bays are provided on the short stretches of roads between the courtyards. Visitors can also park directly in front of the houses but of course, they will be blocking the cars in the house. I prefer to discourage parking in the green at the center of the courtyard.



Serious parking

In Malaysia, people will occasionally put up tents on the street in front of their homes to hold communal events like weddings, funerals or thanks-giving ceremonies. Neighbours accept this, and traffic that normally passes through have to be diverted. Guests then park anywhere they can, on the grass verge, sidewalks...

In the 'honeycomb' cul-de-sac layout, the tents can be put up in the central green area. Some guests can park their cars in the short connecting streets, but most will have to park on the distribution roads outside the cul-de-sac.



A bit tight but still better than the present situation with terrace houses.

[Monamogolo]

Mazlin, Have you considered incorporating footpaths for pedestrians, and thereby shortening some of the distances from homes to shops, or main roads where busses can be found?
Or have middle class Malaysians decided walking and collective transit is only for the poor? (I don't mean to be rude and tactless, but in several of the countries I work, middle class people consider walking in public to be beneath their dignity and status.)

[mazlin]

Prairiesheep,

I had hoped to find an international sign that showed a figure almost like a question mark, with an arrow head at the end pointing back at you. I wonder what the process is to get a sign recognized by the international community.
Preferrably the sign would be self explanatory with no lettering (cul-de-sac is so long at 10 characters).

This is a suggestion:


But I prefer to use the sign used in the Netherlands for "woonerf":



The Dutch invented the concept of the 'shared streets' for residential areas where pedestrians have priority over cars. here the speed of the cars is reduced by traffic calming measures backed up by traffic regulations. In the 'honeycomb' layout that I am proposing, rounabouts and very short stretches of straight roads should limit car speed to about 15km per hour (running speed) or hopefully less.
The 'woonerf' sign implies 'no through traffic', although the road in question might not be a cu-de-sac.

[mazlin]

Mazlin, Have you considered incorporating footpaths for pedestrians, and thereby shortening some of the distances from homes to shops, or main roads where bu.ses can be found?

Or have middle class Malaysians decided walking and collective transit is only for the poor? (I don't mean to be rude and tactless, but in several of the countries I work, middle class people consider walking in public to be beneath their dignity and status.)

At the risk of being rude and tactless to my fellow countrymen, many Malaysians prefer not walk. Evening, leisurely walks are ok, but walking even a kilometer or so to go somewhere in the hot humid climate, and risking sudden downpours of tropical showers, is not something people like to do. This attitude probably cuts across income groups; but of course the poor have less choice.

In theory your suggestion is a good one, especially where the cul-de-sacs are deep. But there is a cost to providing footpaths, plus there is a trade-off against privacy. And there will always be people who prefer to live in more isolated cul-de-sacs.

In the project in Kuantan that I showed above, the footpath that rings the site is more recreational, providing short-cuts to neighbouring cul-de-sacs , but not much else. It was requested by my client as a selling point. The 15m (50') main road in the middle already provides a direct route to the shops and bus stop;it is only about 400m from the furthest house to the bus stop on the main road.

In another project shown below, the local planners asked for connectivity and we got it by putting in side lanes between some of the houses. Actually, the total footpath area is less than the other one.



But I am not sure connectivity is always better. In yet another project, I put cul-de-sac housing opening onto a street with shops that will be part of a small downtown area. There I sealed off the cul-de-sac from through pedestrian traffic.

[Streck]

Mazlin:

Very innovative design and follow through on development of concept. Very nice renderings of the buildings for illustration purposes.

It appears that there is basically one car space per unit. That would be a problem here. Typically there are two cars per unit, and when there are teenagers there may be three or four for a few years. Many times, independent adults share a single housing unit, so this too would mean two cars.

The houses at the acute points of the cul-de-sacs would appear to have a parking shortage problem with only one space per unit - not to mention guest parking. I understand that this may not be a problem in your area.

You have very pleasing aesthetics in your housing design, but I also question the prominence of garage doors or carports that are not always "tidy."

Your generous roof overhangs are a pleasant feature, too. We prefer to have structures (including roof overhangs) at least 20 feet apart to lessen the possibility of fire from one house spreading to another.

I wish you good luck on your project designs. Please let us know your progress. I would like to see some photos of your constructed projects.

I like your cul-de-sac design.

Combining the two colors (blue for information/attention and green for green space/residential) makes it seem residential friendly. And does not use Red - Danger - Dead End!

Its meaning can become universally clear without lettering as it is more commonly seen in context.

Thanks.

[HeartlandCityBoy]

It appears that there is basically one car space per unit. That would be a problem here. Typically there are two cars per unit, and when there are teenagers there may be three or four for a few years. Many times, independent adults share a single housing unit, so this too would mean two cars.

The houses at the acute points of the cul-de-sacs would appear to have a parking shortage problem with only one space per unit - not to mention guest parking. I understand that this may not be a problem in your area.

There is something available called mass transit, as well as walking and biking. Much better alternative IMO than having several cars...

[Richmond Jake]

There is something available called mass transit, as well as walking and biking. Much better alternative IMO than having several cars...

In which world do you live? Not every community can provide mass transit. It's based on an economy of scale. In many communities, the demands of life and family patterns cause the need for multiple vehicle ownership. Like it or not, that's the way it is.

[HeartlandCityBoy]

So shouldn't they make an attempt to become less automobile dependent?

[KSharpe]

And who is "they"?

[HeartlandCityBoy]

They is any community that is auto dependent

[Tide]

They is any community that is auto dependent

Ok, tell me how to run a mass transit system in my situation...

County almost the size of Rhode Island. 150k people, spread out in all corners. Jobs are manufacturing and large lots (500acres+) and spread out. The rest of the jobs are in either a highway strip outside the county or the major city 200k+ population a good 30-35 minute car ride.

We have a train line, not commuter from the County seat (pop 6,500) to the southern reaches. There is a rural mass transit system of both dial a ride (quite expensive I hear) and a small bus route that is basically just a transfer system to get anyone who uses it to the more "major" tranist hubs.

I actually would say the "mass transit" we have in the county is the County School Board Bus System.

[mendelman]

HCB, RJ and Tide....this thread is about good cul-de-sac design, not mass transit. Stay on topic or start another thread. And HCB...watch it, you're starting down the one-trick ponyism path again. mendelman

[Tide]

HCB, RJ and Tide....this thead is about good cul-de-sac design, not mass transit. Stay on topic or start another thread. And HCB...watch it, you're starting down the one-trick ponyism path again. mendelman

Doh! The One Trick Pony got me!!!! I apologize Mr. Moderator.

I am, however, encouraged at how well this thread has survived and the discussion that has come out of it.