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The Sneckdown

It’s extremely rare for Auckland to get snow and even if it does happen, it would never be heavy enough to give us some sneckdowns. So what is a sneckdown?

It’s a shorter way of saying snowy neckdown and a neckdown is another name for a kerb extension.

Kerb extensions are described well on the Streets wiki as (note: Americans use curb instead of kerb):

Curb extensions are extensions of the curb line into the street, reallocating a portion of street space to pedestrians or ancillary uses. Curb extensions are one of the most effective traffic calming tools, and can be used in a variety of ways, both at corners and mid-block. They can mostly be found in residential neighborhoods and downtown commercial areas. Also known as bulbouts, popouts, or neckdowns, curb extensions increase drivers’ awareness of pedestrians, decrease crossing distance, reduce pedestrian exposure to traffic, and reduce traffic speeds. They are also referred to as neckdowns because they create a narrowing of the street at intersections or midblock.

Studies show curb extensions combined with a marked crosswalk increases yielding of vehicles to pedestrians waiting to cross the street. [1] Curb extensions also have a number of other purposes:

  • Providing a prominent area for landscaping, public art, lighting fixtures, or freestanding A-frame signs.
  • Providing an area for newspaper vending boxes. Cities or merchants sometimes want to remove vending boxes to de-clutter the sidewalk, but newspaper boxes are protected by the First Amendment to the U.S. Constitution, and must be accommodated. A large bulbout can provide a good compromise location.
  • Corner bulbouts carefully constructed to neckdown a street also eliminate high speed turning movements (particularly right turns), increasing safety for all users of the street.
  • Providing protection for vehicles parked behind the bulbout.
  • Providing an area for street trees, other landscaping, or a groundwater recharge area, also known as a “bioswale

We actually have a few kerb extensions in Auckland, for example there was one in the Lorne St photo yesterday but they are not widespread. Where they do exist they are usually added as part of a wider streetscape upgrade. I think AT should be looking to roll this type of treatment out across a wide area of Auckland as they can be great for slowing cars down in residential areas however if they were to do that I could see them being forced into conducting numerous traffic studies, multiple rounds of consultation and subject to protest from some residents and local businesses worried about a loss of on street parking or having to drive slower.

What makes the sneckdown so interesting is it because it is caused by weather it happens without consultation and there is nothing that can be done to stop it. When the snow is ploughed it moves it to the edge of the road where it forms in piles creating temporary kerb extensions that people quickly adapt to. The snow also helps highlight just how much space is on our streets that is generally only used to allow vehicles to corner faster. In effect you could argue that a sneckdown is nature’s way of slowing down traffic and making more pedestrian friendly and liveable streets. Clarence Eckerson Jr who runs the awesome Streetfilms told the BBC “The snow is almost like nature’s tracing paper,” and “It’s free. You don’t have to do a crazy expensive traffic calming study. It provides a visual cue into how people behave.”

The image below shows helps explain the sneckdown

And here’s a video from a few years ago showing them in action.

I imagine that if Auckland were to get a massive dumping of snow we would see huge numbers of intersections that could be easily narrowed down. As the chance of that happening is remote, perhaps it’s time to start trialling this with traffic cones?

17 comments to The Sneckdown

  • Simon

    The unintended consequence of kerb extensions is that they push cyclists out of the shoulder and into the path of motor vehicles. The ones on Station Road in Penrose are particularly bad for this. I’m also not totally convinced that pedestrians crossing a road should be pushed closer to a stream of road traffic.

    • bbc

      Simply have a cycle bypass behind the kerb extension, thereby having the benefit of a narrowed intersection, less road to cross for pedestrians and also a safe turning lane for cyclists in which you don’t have to worry about cars cutting you off by overtaking and then turning directly in front (as always happens in Auckland).

      • This is a traffic island rather than necessarily a kerb extension but shows space for cyclists behind the island. http://goo.gl/maps/BoRaJ

        Simon – this doesn’t push pedestrians closer to a stream of traffic, it creates more space for pedestrians allowing them to stay further away and means IF they want to cross the road the distance is shorter.

        • Walkablecity

          Agreed, except when pedestrians slip on that ice. Trust me, it happens. I grew up where this vid was taken. And as Feijoa mentioned, those planted islands are a problem much like the ice, except here the problem is obscured visibility, and nowhere to stand sometimes.

        • NigelTwo

          The google image shows why these “bulbous curbs” are traps for cyclists. What does the vehicle driver see – straight road.
          These things are the equivalent of large parked car, except the passing driver doesn’t see that.
          I can only think of one example of the slip lane style treatment in the whole of Wellington City (and it’s actually on a roundabout not a ped crossing).

        • grantb

          This is another example I cycle through some times: http://goo.gl/maps/cq31s

          You cycle behind the neck – which I guess does make it an island, but feels connected to the foothpath as it flows out from the path, and slows traffic heading into the roundabout.

          • Luke C

            wow that is a shockers for pedestrians, no crossings at all. Right outside the local shops, and in the middle of a residential area.

        • That is a really nice piece of cycle infrastructure. So frustrating though as CAA is consistently told that cycle bypasses like that are not possible.

    • Jacques

      I don’t like this way of thinking. ‘pushing cycles in the path of motor vehicles’ should not be a problem, ie when a motor vehicle has a cyclist in from of them, they should slow down and stop if need be, not behave as though the cyclist is transparent. More infrastructure can alleviate the problem in the city, but unless there’s also an effort to solve the attitude problem, cyclists will never be safe out on the open road. Do we want to solve this for Auckland or for all of NZ?

      • Loraxus

        I understand what you are saying Jacques, but even in the Netherlands, where car drivers are much more courteous to cyclists, pushing cyclists into the middle of road like this would only ever be appropriate in a 30 km/h or less zone. On 50 km/h or higher-speed roads, such kerb buildouts need to be avoided / have bypasses / have a minimum width left over.

        That said, in many cases, it is actually easy enough in Auckland to massively reduce the width of a road or intersection without endangering cyclists in this fashion at all. Our intersections are so massively wide, you’d think our residential suburbs were all delivery routes for oversize trucks.

    • Steve D

      This issue pretty nicely demonstrates that “walking-n’-cycling” is not a monolithic whole, the way it’s often lumped by transport policymakers. Sometimes peds and bikes do have conflicting needs.

      The cut-throughs (essentially a bike-only slip lane!) that bbc and Matt talked about are certainly better (for both peds and bikes) than a giant blown-out intersection, but they do mostly negate the benefits of the kerb extension as being “part of the footpath”. Whether that’s more important depends on the context: I think in the CBD and town centres having a stronger value as a place is more important than letting cyclists take left turns at speed. These sorts of streets should be 30km/h anyway, which should solve most of the issues for bikes sharing the turn with cars.

      On intersections between arterials and local streets, though, where only the side street has a neckdown, the slip lane is probably a good idea.

  • Feijoa

    I’ve never understood why when they add ‘neckdown’ islands here, particularly those added with raised table speed humps, they plant the island intensly so you can’t cross there.

    A year or 2 ago they did this with the speed humps on Motions Rd outside the zoo. There are lots of other examples, almost all of the suburban street calming added in the 80s and 90s is the same.

    • Loraxus

      Because they don’t trust you to cross safely there, unless it is designed to be a crossing. They feel you might feel like you had right of way and step out heedlessly, unless it has a zebra on it too, and the rules are very strict about where they allow zebras to go, basically only where there’s lots of pedestrians already (TOO strict, in my view).

  • Peter H

    Loraxus
    “Because they don’t trust you to cross safely there” I think this is the reason the have strict rules about where they allow zebra crossing. The rule maker thinks people may walk into traffic that’s not giving way to the pedestrian’s right of way.
    This from an AA UK survey.
    “fatalities ratio on pedestrian crossings is 6 times higher in Norway than in the Netherlands”
    “In the Netherlands, the pedestrian is not specifically asked to pay attention before using a pedestrian crossing”
    “In Great Britain and Norway, a sign (e.g. with the hand) from the pedestrian gives him right of way”
    http://www.theaa.com/public_affairs/reports/aa-pedestrian-crossings-survey-in-europe.pdf

    Of cause in the Netherlands there are lots of ped crossing and they put more enough into a self explaining transport network. Like ped crossing is where people walking have right of way. No need to thank or ask people in or on wheel vehicles for stopping.

  • Ted E

    Does the pedestrian have right of way at uncontrolled intersections in the USA?

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