I submitted my contributor form to Greater Greater Washington (GGW) today and GGW’s staff gave me the green light so my first blog post should be published on GGW sometime next week. Since GGW’s staff asked me to write differently than I write on my personal blog, I wanted to share the version I wrote before GGW’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 GGW post after it is published, but as a teaser I’m sharing my longer and more technical version below.
A bike boulevard (DC region refers to neighborhood greenway as bike boulevard) is an outdated idea currently being used by many US cities to improve safety for all street users.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:
- 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, The Netherlands, which is a suburb of Utrecht, has implemented a citywide traffic diversion plan.
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.
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, The 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.
- Extremely low traffic speeds, including traffic calming as needed. Below is a bayonet traffic calmer in Delftweg, The 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.
- Shared space, without sidewalks, with motorists sharing the space with pedestrians and cyclists, like a woonerf.
- Oasis greenways must be continuous for at least several blocks and have connectivity through busy intersections.
- 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, The Netherlands shows the terminal vista effect.
- 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, The Netherlands shows a grasscrete street.
- Park and parking strip. They must have a wide area where on-street parking, parklets, trees, vegetation, and play areas are located.
- 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.
- 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.
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?