Cul de SacIn my opinion and the experience I’ve had as a City Engineer, roads in general are a blessing – but Cul de Sacs are a curse. And I’m not just talking about the planning aspects in terms of traffic circulations and the creation of neighbourhood identities, but on the cost of providing services to these half finished thoroughfares.

It appears that I am not alone in this slightly divisive feeling…

But this fall, Virginia, under the leadership of Gov. Tim Kaine, became the first state to severely limit cul-de-sacs from future developments. New rules require that all new subdivisions attain a certain level of “connectivity,” with ample through streets connecting them to other neighbourhoods and nearby commercial areas.

If subdivisions fail to comply, Virginia won’t provide maintenance and snowplow services, a big disincentive in a state where the government provides 83 percent of road services.

In fact, some municipalities around North America, such as Naperville, Illinois, have taken to placing Cul de Sacs at the bottom of the priority list for snow removal:

Why are cul-de-sacs plowed last?

Cul-de-sacs are not plowed last. They are just the most time-consuming streets to plow. On average, it takes 35 minutes to clear a cul-de-sac of snow. That is eight times longer than it takes to plow a through street of the same size. Cul-de-sacs are also more difficult to clear because of the limited space in the parkway to dump snow without burying driveways, mailboxes, street lights or fire hydrants.

The increasing number of cul-de-sacs and other dead-end streets has multiplied the amount of time it takes to clear streets in Naperville. Today, Naperville has more than 1,200 Priority Three streets, compared to about 350 such streets just a few years ago.

Source: Snow Removal – Frequently Asked Questions – City of Naperville

The Not So Humble Cul de Sac

The Cul de Sac has been the domain of the real estate agent with the promise of higher property values, safer streets and kids riding their bikes around the peaceful pavement, but the reality is that the kids are disconnected from the rest of the community as the inter-connectedness is gone, and in some instances, property prices have plummeted. Among the many reasons for the angst felt by planner and engineers alike, the Cul de Sac is partly responsible for an increase in trips generated per day as a network dominated by Cul de Sacs fails to provide the necessary intersection nodes necessary to support small scale commercial activities, and forces these activities to the main roads, strip malls and box stores.

But appearances can deceive. All indications are that cul-de-sacs are less safe than pre-war neighborhoods layed out in the traditional grid. An article by Philip Langdon in the Jan/Feb 2009 issue of New Urban News shows that, according California accident statistics, cul-de-sac neighborhoods see more car crashes than the denser pre-war neighborhoods. The older grid patterns also have quicker response times for fire trucks and other emergency vehicles. And accidents and crimes in the older neighborhoods are more likely to be reported faster since they have more people on the streets.

Source: Death to Dead Ends – Fast Company

Is there a Future for this Relic of the Age of Happy Motoring?

Any form of street that takes longer to plow, is measurably less safe and may raise the cost of providing services to all residents is likely to go the way of the Dodo as belts are tightened and greater emphasis is placed on efficiency and sustainability. It could be that the age of the Cul de Sac as a planning tool and road network feature is coming to an end. I must say that this brings me no sadness.

Published by Mike Thomas

Mike Thomas P.Eng. ENV SP, is the author of and Director of Engineering at the City of Revelstoke in the Interior of British Columbia, Canada.

2 replies on “The High Cost of the Cul De Sac”

  1. I’m responding to the cul-de-sac topic, but please bear with me for a little ranting.

    I live in Northern Virginia where, along with the District of Columbia and Maryland, we’ve just had record-breaking winter snowfall total for our area – from 54 to 72 inches across the region since Dec. 18. I know that’s par for the course in other places, where they get a lot of snow on a regular basis.

    But here, this only happens once every decade or 15 years, so it’s a big deal when we get a lot of snow. Many people don’t know how to drive in it or use common sense. In other years, we get mostly 1-2 inch snowfalls, with an occasional, once every year or three maybe, \big\ (for us) storm of 10-18\. I have lived in the DC metropolitan area for 45 years, and population (thus traffic) has grown exponentially in that time – over a million in my county alone, not counting DC or other nearby counties.

    I’ve been told that the entire state of Virginia has the same amount of snowplows as New York City alone has; populations (state total to NYC total) are about the same, but terrain is not. You can imagine how that works out for clearing snow here. And it is not cost effective to keep and maintain the fleet of plows you’d need to handle an atypical amount of snow that the state gets so rarely.

    Cul-de-sacs – I’ve lived on one for 25 years, at the end of a pretty long street in a subdivision. Not my ideal choice, but here we are. My gripe is plowing. I’m amazed that Naperville, IL spends 35 minutes on plowing cul-de-sacs. Here, they give it a lick and a promise for maybe 5 minutes – no way it is ever \cleared.\ It’s always seemed to me to be common sense, if it is a moderate amount of snow, for a plow to continue along the side as they come up the street into the cul-de-sac and make the loop. That way all driveways (once they dig out the plowed snow) can access the street. Many times we are plowed where they push it once to one side, then once to the other (like a \Y\), back around and head out. We have to dig about another 1 1/2 to 2 car lengths to reach the plowed part of the street. Obviously if there is a lot of snow, the plow would need to either pile it in the center, or push to some available place with no driveway or mailbox. I guess that’s what they try to do, but amazingly clearing anywhere close to the driveways doesn’t seem to be a priority.

    Even when we get a plower who does a better job (God bless them!), I have watched and fail to see how it would take 35 minutes to make the cul-de-sac passable. I grant you that my type of cul-de-sac may not be typical elsewhere. Picture it as a clock: at 7-9:00 half a lot of community property (no driveway), at 11:00 we have one house’s driveway; at 12:00 we have a \pipestem\ driveway with 4 houses (they dig that and their own individual driveways out themselves); then at 1:00 another house’s driveway; and finally at 4:00, the last house’s driveway. We have mailboxes on posts at the street, and the way they and the driveways are arranged, there’s not much parking on the 1-4:00 side. None of my neighbors parks on the cul-de-sac on a usual basis; never during snowstorms. Yet snowplow operators rarely clear it much at all.

    In 1996, the last time it was similar to this year with multiple blizzards, a neighbor got injured while sledding on a hill behind the community property (storm drainage area). We never got plowed on the whole street during these storms, and were not able to drive out for 2 weeks. The medics could not use our street to reach our neighbor, and had to go to extreme measures to get to her. For a few years after that, we got plowed soon after it snowed, and often, but not lately.

    Part of the problem is that the state uses a lot of sub-contractors to plow, and there apparently is no way to have them taught on how to plow a cul-de-sac. By the time they hit the tertiary roads in a subdivision, they are tired from multiple 12-16 hour shifts, and just want to get done and out. The state imported plowers from North Carolina and downstate earlier this week; many had not seen snow like this before.

    Thanks for letting me rant. It’s an imperfect world, that’s for sure.

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