Neighborhood Greenways Are Cool, But Oasis Greenways Are Awesome!

I submitted my contributor form to Greater Greater Washington (GGWash) today and GGWash’s staff gave me the green light, so my first blog post should be published on GGWash sometime next week. Since GGWash’s staff asked me to write differently than I write on my personal blog, I wanted to share the version I wrote before GGWash’s staff asked me to shorten my blog post and make it less technical. As I wrote in this post, I knew I would have less control over my writing when I started posting on other blogs. I’ll share my GGWash post after it is published, but as a teaser I’m sharing my longer and more technical version below.

Update: here is my first GGWash post!

A bike boulevard (DC region refers to neighborhood greenway as bike boulevard) is an outdated idea currently being used by many US cities to improve safety for all street users. An oasis greenway is a new approach that represents the future of safe street design. An oasis greenway is a long series of interconnected low-speed, low-volume, shared-space, vegetated linear parks created from an assembly of residential streets. As the below video shows, an oasis greenway is based on the Dutch woonerf.

According to Tom Bertulis’ 167-page thesis, Oasis Greenways: A New Model of Urban Park and Bikeway within Constrained Street Rights-of-Way, the nine elements that any given facility must include to be called an oasis greenway are the following:

  1. Extremely low traffic volumes, including traffic diversion as needed. While many cities in the US are focused on traffic diversion on a street by street basis, several cities in the Netherlands are focused on traffic diversion on a neighborhood or citywide basis. Houten, Netherlands, which is a suburb of Utrecht, has implemented a citywide traffic diversion plan.
    Houten Street Network

    Houten’s traffic diversion map. Source: ITDP

    As the below map shows, motorists are routed from their neighborhood road (green) onto a connector road (brown) that directs them to the outer ring road (yellow). Motorists must drive all the way around Houten until they reach another connector road that connects them to their destination. Since cyclists and pedestrians can travel through the traffic diverters, they can travel quicker than motorists through Houten.

    Houten Street Network zoomed in

    Neighborhood level of Houten’s traffic diversion map

    Watch this video to learn more about Houten.

    Since Houten was originally designed with traffic diversion, it is a unique city because it didn’t need to be retrofitted. Most, if not all, US cities will have to retrofitted with traffic diversion so here is a neighborhood retrofit example from Utrecht, Netherlands. US cities should be able to relate to this retrofit example much easier than the approach that Houten took with its citywide traffic diversion plan.

    While no US city has implemented a citywide nor neighborhood network of traffic diverters, Portland, OR has several traffic diverters. Here is a diagonal traffic diverter in northeast Portland.

    2015-07-26 16.21.38

    Diagonal traffic diverter at NE Tillamook St and 16th Ave. Photo: Ray Atkinson

    Diagonal traffic diverter at Tillamook and 16th

    Diagonal traffic diverter at NE Tillamook St and 16th Ave

  2. Extremely low traffic speeds, including traffic calming as needed. Below is a bayonet traffic calmer in Delftweg, Netherlands. While the street is two-way, the bayonet forces motorists to take turns going through the bayonet. Cyclists have a two-way trail so they can avoid the bayonet.

    DSCN0394

    Delftweg’s bayonet traffic calmer. Photo: Ray Atkinson

  3. Shared space, without sidewalks, with motorists sharing the space with pedestrians and cyclists, like a woonerf.

    Bell Street Seattle Before & After Shared Space

    Shared space on Bell Street in Seattle, WA

  4. Oasis greenways must be continuous for at least several blocks and have connectivity through busy intersections.

    Portland Neighborhood Greenway Crossing

    Portland neighborhood greenway crossing. Photo: Steven Vance

  5. Terminal vista. They must make use of the “terminal vista effect,” where the line of sight straight down the street is partially obscured, usually by trees or an on-street parking chicane. The below woonerf in Delft, Netherlands shows the terminal vista effect.

    Delft woonerf

    Woonerf in Delft, NL. Photo: Ray Atkinson

  6. Parklike, which refers to using grasscrete as the default in areas that aren’t travel-ways for cyclists and pedestrians. The below photo from Haarlem, Netherlands shows a grasscrete street.

    Grasscrete in Netherlands

    Grasscrete street in Haarlem, NL. Photo: Dan Burden

  7. Park and parking strip. They must have a wide area where on-street parking, parklets, trees, vegetation, and play areas are located.

    Oasis greenway park and parking area

    Rendering of park and parking strip. Rendering: Tom Bertulis’ thesis

  8. Minimal parking footprint. They must minimize the parking footprint based on a parking needs analysis. Use the below illustration to compare parking footprint of a traditional street with parking footprint of an oasis greenway.

    Oasis Greenway vs. Traditional Street

    Source: Tom Bertulis’ thesis

  9. Small and large play areas. They must have both small and large play areas, with the small play areas referring to the Park & Parking Strip and the large play areas referring to Oasis Greenway sections with “ultra-low volumes” where the play area temporarily becomes the entire cross-section of the street, not too different from when hockey is played in the street.

    Street Hockey

    Street hockey. Photo: Jonathan Tavares

While no street in the US has been designed with all nine elements of an oasis greenway, a few cities have experimented with several elements of an oasis greenway so please don’t think that an oasis greenway can only be designed by the Dutch or Europeans. Would you like to see an oasis greenway constructed in your neighborhood? If yes, where? If no, why not?

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One thought on “Neighborhood Greenways Are Cool, But Oasis Greenways Are Awesome!

  1. growingeastcounty says:

    Ray: great post on GGWash! The ideas you suggest might be a great solution to our community’s concerns about traffic calming. I’ll send you an email with some info about our campaign to #buildabetterBurtonsville, but for the rest of y’all, learn more at http://www.facebook.com/fix198now

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