CDOT Pilots Bike Lane Treatment Inspired by Dutch Protected Intersections

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The new treatment at Washington/Franklin, looking north. Photo: John Greenfield

As part of the Loop Link bus rapid transit project, which includes the construction of protected bike lanes on Washington, Randolph, and Clinton downtown, the Chicago Department of Transportation is trying a kind of intersection treatment that’s new to our city. Inspired by Dutch-style “protected intersections,” they’re installing special concrete curbs and islands in an effort to shield cyclists from turning vehicles.

The Clinton two-way lane was completed several weeks ago, and the Washington protected lane, which is separated from moving cars by the BRT system’s island bus stations, as well as concrete curbs and flexible plastic posts, is largely finished. CDOT hasn’t yet begun work on the Randolph PBL, pending the completion of a construction project at Block 37, but most of the separation will come from posts, not concrete, according to spokesman Mike Claffey.

The department recently completed the new intersection treatment at the southeast corner of Washington/Franklin. A similar approach is planned for Washington/Dearborn, Randolph/Dearborn, Randolph/Franklin, and Randolph/Canal. “Our goal is to provide separation up to the intersection to minimize conflicts between bikes and cars.” Claffey said. “We’ll monitor them to see how effective they are.”

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Still from Nick Falbo’s video, which illustrates how protected intersections work.

Before we take a look at Washington/Franklin, here’s some background on how protected intersections function. These designs use curbs, islands, pavement markings, and bicycle-friendly traffic signals to ensure that the safety offered by protected bike lanes isn’t lost when a cyclist gets to a cross street.

A key aspect of protected intersections is the creation of proper sight lines between drivers and bicyclists. Motorists who are turning right are positioned at a 90-degree angle to the bike lane with enough time to see bicyclists riding straight through the intersection and hit the brakes if necessary. This prevents “right hook” crashes.

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Still from Mark Waagenbuur’s video, showing how protected intersections prevent “right-hook” crashes.

Protected intersections have been common in the Netherlands for quite a while. Recently, the concept has become more familiar to U.S. bike planners and advocates, partly thanks to some useful videos explaining how the intersections work. Several years ago, Mark Waagenbuur from Den Bosch, Netherlands, author of the Bicycle Dutch blog, published this video, which shows that many typical American street intersections have sufficient space to be modified into protected intersections.

The idea became more widespread in 2014, when Portland-based urban planner Nick Falbo, created a website about protected intersections, featuring studio-quality animation. Since then, two Dutch-inspired protected intersections have been built in Davis, California, and Salt Lake City.

Steven Vance has done more research about protected intersections than I have, so I’ll let him provide his initial impressions of the new installation:

From what I can see from the placement and design of the curb and concrete islands at Washington and Franklin, the intersection doesn’t meet the design standards of a Dutch-style protected intersection because it doesn’t provide the setback bike lane, making space for a right-turning motorist to see a bicyclist with the correct, nearly right-angle sightline, nor does it provide a good amount of space for queuing bicyclists.

To build it in the way shown in Waagenbuur’s animation, the main change would be rounding the curbs and concrete islands CDOT already built, and setting back the stop bars and crosswalk markings on Franklin.

While the new treatment may not be a full-fledged protected intersection, my impression is that it will do some good for preventing right-hooks. Moreover, CDOT deserves credit for trying something new. Hopefully they’ll pilot a straight-up Dutch-style intersection at another location in the near future.

To give you an idea of how the Loop treatment functions, here are a couple of clips I took while riding east and north via the facility.

  • The biggest issue is likely due to a misunderstanding on how not just Dutch intersections, but the entirety of how their streets are designed and built. As Wagenbuur explains in another video (which I’m too lazy to dig up at the moment), Dutch street design focuses on keeping the roadway as narrow as possible for the circumstance. As a result, a staple of American roads in many places, the paved shoulder, really sees little use on Dutch streets. They also don’t build very many roads to “ultimate width” in expectation of “future demand” compared to what we do here. The Dutch are not afraid of removing lanes when necessary or unused either.

    In addition to the narrower roadway, there are general guidelines for how far from the traveled way the bikeway should be, which increases by speed (though generally has to stay within 10m to be considered part of the adjacent road). As a result, a Dutch bikeway approaching an intersection that would have signals is generally already far enough to provide the space and can sometimes be too far. There is an optimal range, two to five meters, outside of which the crossings get more dangerous.

    With that background, a clearer picture is available of what is not right with the ones above. Noting that there is no “standard” Dutch intersection and that they literally come in numerous shapes and configurations, including at numerous Dutch intersections without signals, there nonetheless good and not-so-good examples available. I’ll reserve final judgement until I actually ride them, but what appears to be the issue with the ones here is that they’re being added to a street design while not 100% understanding how they should come about existing in the first place.

    Protected intersections are conceptually the result of two separated bikeways intersecting in a bulbout. The protective island is what’s left after cutting the bikeways through. Ideally, those bikeways would already be within the two to five meter range from the roadway (maybe traveled way) on the approach, eliminating the need to do any bending, but if they’re outside those ranges, they should be bent the appropriate direction to achieve it.

    However, although the concept is based on extending bikeways, protected intersections don’t need the separated bikeways, as is the case here. They are actually great solutions for routes with no formal bikeways at all just as long as they’re designed well. In addition to the other concerns presented, that also includes making sure the bend angles are designed for bicyclist speeds and including stuff like angled curbing on the bikeway side of the island (or really any concrete curb facing a bikeway).

    CDOT has made a good effort here, hopefully they look to improve on them in the future.

  • Wow, basically those corners want a bicyclist to stop and put a foot down, period.

  • Scott Sanderson

    Wow this is awesome and I love it. Way to go Chicago!

  • johnaustingreenfield

    I didn’t put a foot down, even when I was waiting for a signal to go north on Franklin. Then again, after six years of bike messengering, I’m pretty good at track standing.

  • disqus_1pvtRUVrlr

    Poor execution of the concept. The acute angles to make a left turn, confined space and staging area, and elliptical islands that are undersized totally compromise the effectiveness and functionality. Fail CDOT.

  • J

    Thanks for the insight! This is very useful. I would add that while the designs may still not be ideal, they are certainly moving in the right direction, away from the “mixing zone”, which I’m pretty sure doesn’t exist in the Netherlands.

  • J

    While your assertion that the angles may be too tight, I think it’s important to keep in mind that this design is 1000x better than the “mixing zones” that are being installed almost everywhere else in the US. This design, even with its faults, still slows vehicle speeds and improves visibility dramatically, providing a much safer and more comfortable environment for a wide range of people on bicycles. It also creates a more predictable environment for drivers, reducing driver-cyclist animosity.

    All around a very big step forward for US bicycle infrastructure.

  • Mixing zones do exist in The NLs, but they’re definitely not considered best practice and I doubt many new ones are being built. Instead, the current ones are being removed as part of maintenance and street redesigns. Here’s one such transformation in Utrecht: (location on Google Maps:,5.0926325,3a,75y,246.39h,67.4t/data=!3m7!1e1!3m5!1scia5PPRX2kYtaRYHCc0-HA!2e0!5s20090401T000000!7i13312!8i6656).

    Here are some other mixing zones from various other places in The NLs. I know that there are more, especially in Rotterdam from what I hear, but these are just a couple that I know of from personally seeing/riding through them.


    Utrecht again:,5.082971,3a,75y,326.54h,74.58t/data=!3m6!1e1!3m4!1sdogkoyYr88Ws92LlB2S26Q!2e0!7i13312!8i6656


  • J

    Interesting. Thanks for the information. It’s good to see US cities starting to adopt designs more in line with best practices, instead of building brand new infrastructure based on outdated designs that are actively being replaced.

  • XonaTanoX

    As someone from the Netherlands, I’m surprised to hear that seperate biking lanes aren’t actually common outside of the Netherlands.

    I’m not an active cyclist, but I do know that riding a bycicle in the Netherlands feels safe and pleasant, especially at intersections as mentioned above in the video.

    I hope to visit the U.S. someday, at least I know now that I should rather rent a car then rent a bike, because as someone who is used to the dutch way of cycling, cycling in the U.S. will be a major change for me.

    If anybody wants to visit the Netherlands anytime soon, be sure to rent a bike, because it’s safe, it gets you to most locations faster than by car, and it’s also a cheap way of transportation during your vacation in the Netherlands :)

  • Yes, the biking is quite different here than there; I know no Dutch people who prefer biking here to there. But if you’re in SoCal, I’ll show you around!


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