BY REUBEN, ON MAY 29TH, 2013
There has been a lot of discussion in the local bicycling scene about cycle tracks lately. “Cycle track” is a bit of a generic term. It may refer to a one-way or two-way facility. It may refer to something at street level or at curb height. It may create separation between cyclists, motorists, and pedestrians using paint, medians, or curbs. It may or may not include a floating parking lane. It’s complicated. There are any number of design details that may differ from one cycle track to the next. We need to be careful when using the term cycle track, as the term on its own is not particularly descriptive.
Today, I want to discuss one of these variables – elevation. There are a lot of ongoing discussions about whether cycle tracks should be at street level, or curb height. Curbs play a critical role in this discussion. In the vast majority of urbanized areas in the US, roadway space is demarcated by the use of a standard concrete curb and gutter. There are local variations, but the gold standard is a gutter pan somewhere between 12″ and 24″ in width and a 6″ tall curb. There are two primary functions of this curb: 1) to convey stormwater, and 2) to clearly demarcate exactly what is on the street and what is off the street.
For a number of years now, curbs have been becoming more and more difficult to design, primarily because of ADA ramp requirements. I want to be clear that I fully support ADA compliance and the new rules, but it is fair to say that they add a new level of complexity to intersection design, especially at signalized intersections. There are very specific rules about ramp grades, placement and orientation of truncated domes, placement of signal poles, push-button pedestals, level landings, crosswalk locations, and other features. Engineers who have been designing curb ramps for decades are scrambling to re-learn their trade.
American bicycle planning for decades has designed bicycle facilities that fit well into one of two categories: on-street or off-street. For the most part, this question is synonymous with “which side of the curb is it on?” On-street bike facilities are traditional bike lanes, and recently, facilities such as lanes marked with sharrows, or even bicycle boulevard facilities. Off-street facilities are trails or paths, such as a recreational trail or a sidepath. There have long been lines drawn in sand about whether cyclists are better off in the street mixed with traffic or separated from traffic on sidepaths. Off street trails have been accused of being not much more than glorified sidewalks (which nearly everyone can agree is not a great place for adult cyclists). On street facilities have been criticized for failing to create adequate separation between bikes and cars. Most of us agree that off-street trails are great at mid-block locations, but the intersections, where cyclists have to leave the path and enter the roadway, is where the real safety concerns are. Where do cycle tracks fit into this discussion? Which side of the curb are cycle tracks on?
Any discussion of cycle tracks is incomplete without a discussion of Denmark and The Netherlands. In both of these countries, cycle tracks occupy a bit of a middle ground somewhere between on-street and off-street – a middle ground that doesn’t really exist within the US. In both countries, curbs are a bit, eh… different. Curbs are rarely a 2.5′ wide piece of concrete. Only occasionally do Dutch streets actually have a gutter pan, and curbs are often somewhere in the 2″-4″ range. In both countries, cycle track design often uses half-size curbs, subtly demarcating space with 1″-2″ change in elevation. There is nothing similar in the US.
Dutch and Danish cycle tracks have a remarkable way of allowing cyclists to pass through intersections without ever feeling like they are going up or down a ramp, across a curb, or through a gutter. In a sense, they strike a critical balance between the messages that have stymied discussions of bike facilities in the US. At mid-block locations, they provide protection and a low-stress environment for cycling similar to off-street trails. At intersections, they seamlessly transition cyclists to an on-street location where they have the benefits of additional visibility provided by on-street bike lanes.
Take a look at this image below, which is a pretty typical Danish intersection design in the city center where space is scarce. In this image, you can see the cycle tracks extending away from the corner, and as they do, the cycle track is on top of a smallish 2″ or so curb. As the cycle tracks approach the intersection, the curbs just sort of disappear – the 2″ of elevation difference just sort of absorbed into the roadway surface. While cyclists are separated from motorists in mid-block locations by a small curb, they are able to transition seamlessly to street level at intersections. Brilliant.
This type of design is pretty straight forward and could be reproducible in the US relatively easily. Here’s a video from John Allen of a bikeway on Concord Ave in Cambridge, MA that more or less implements this design (NOTE: I am not a John Allen fan, but the video does a decent job at giving you a feel for the bike facility – feel free to watch the video on mute). I actually like this design, though I don’t think it’s quite what folks have in mind locally when they are discussing cycle tracks.
In The Netherlands, it is common to see something similar to the image below. Right on the corner there is a little raised roundish median (which a co-worker of mine once dubbed “the biscuit” and I see no reason to use any other term). A lot of folks prefer this design to the Danish design above because it offers cyclists a bit more protection if they’re waiting for a light right on the corner. Yet again, notice that there is no clear ramp for cyclists to navigate, and no gutter pan. Any changes in elevation between the roadway and the cycle track are subtle at best. The cycle tracks in the photo below have the trademark dutch red coloring, and if you look closely, you can see where the red coloring stops near the biscuit. Other than color, the transition of the cycle track to the intersection is seamless.
In the photo above, is the cycle track an on-street facility or an off-street facility? Is it proper to think of a facility like this as part of the sidewalk, or part of the roadway? In US terms, is this cycle track in front of the curb, or behind the curb? I suspect only an American (blogger) would ask these questions.
Also, a quick clarification that the question of curb-height or street-level, on-street or off-street is mostly meaningless at mid-block locations. It just doesn’t really matter. But it does matter at intersections. Alot.
So what about the cycletracks that exist in the US already? Let’s take a look at a few examples.
First let’s look at Vassar Street in Cambridge, MA. This street has one-way cycletracks that are clearly at curb height flush with the sidewalks. Decidedly off-street. How does it handle signalized intersections? Well, it doesn’t. I can’t find any good photographs online, but it’s pretty visible on Google Maps that the cycle tracks transition to traditional on-street bike lanes several hundred feet before any signalized intersection along the corridor. This design is lovely at mid-block locations, but it doesn’t address signalized intersections.
Below is a design from Evanston, IL of a two-way facility, and I’ll suggest that it is a good example of how cycle tracks should NOT address intersections. Evanston developed a bikeway along Church Street that for whatever reason, they wanted two blocks of it to be at curb height. Please ignore the rubbish bins in the middle of the cycle track and the question of why no attempt was made to visually distinguish the cycle track from the sidewalk space and focus only on the ramp designs. This is an intersection with a driveway, but you could imagine the same thing at a signalized intersection. This is the opposite of seamless, it clumsily uses a standard ADA pedestrian ramp complete with truncated domes and gutter pans. The engineers decided to include an ADA compliant ramp on a bikeway, presumably not for blind cyclists but because a blind pedestrian might wander onto the cycle track. Or is it because all off-street facilities need truncated domes before crossing a roadway? Maybe. Maybe not. I really don’t know, and I suspect these engineers didn’t either so they just decided to include them to be on the safe side. Fair enough. I can respect the decision, though the resulting design is underwhelming and barely comparable to a Dutch cycle track.
However, take a look at this same facility about one block down the road in the picture below. For whatever reason, at this point the same facility has transitioned from a facility that is decidedly off-street and curb-height to one that is decidedly on-street and at street level (notice how there is no middle alternative – it’s either on or off?) Some folks won’t like this design because it lacks a curb or median separating motorists from cyclists. However, there are a few things that I really like about it. Notice how it completely avoids the question of ramps, curbs, or ADA compliance. Cyclists do not navigate gutter pans, ramps, pavement joints, or truncated domes. They are functionally quite different than riding on a sidewalk. Even more, it allows the existing gutter, curb, sidewalks, ADA ramps, crosswalks, etc. to be 100% standard US design.
Ok, I can hear people thinking that I’ve picked some of the worst possible examples of cycle track designs to make my point. Ok, point taken. It’s because I honestly am not aware of great curb-height (or half-curb-height cycle track designs in the US. If you have examples, please let me know. And again, the question is really not about mid-block locations – it’s the intersections that matter, and curb-height cycle tracks complicate what is already a complicated set of rules governing intersection and ramp design.
Now, think of your favorite cycle track that has been developed in the US or Canada, and let’s see how it handles issues like half-curbs, ramps, crosswalk locations, and ADA compliance.
Here are some photos:
All the photos above are street level facilities. They have no impact on curb height, ramps, crosswalk locations, and ADA compliance. Engineers are free to locate pedestrian curb ramps and crosswalks wherever they please. Are there other favorites out there?
Here’s my point: Curb-height cycle tracks introduce a level of complexity to the design of intersections that is unnecessary. I am not aware of a US city that has successfully translated the elegance of dutch cycle track design into a US context with half-curbs and biscuit islands or a full curb-height design that navigated ADA requirements. Meanwhile, cities all across the US have implemented street-level cycle tracks separated from motorized traffic with medians or parking. In many agencies, it is safe to say that the engineers are not champing at the bit to design cycle tracks at all, let alone a facility that requires them to fundamentally re-imagine all of the curb ramps, which are already tricky enough as it is. I am not suggesting that we settle for less-than-stellar facilities. The word I am hearing from cities like New York and Washington DC is that they are having phenomenal success with their street-level facilities.
I do not doubt that US engineers are perfectly capable of designing any type of facility they set their minds to. We are seeing a number of creative bikeway designs emerging from US cities that have figured out ways to navigate some of these questions. I will be the first to tip my hat to the first US engineers and agencies that are able to implement the grace of Dutch cycle tracks. In the mean time, my hunch is that US cities will have the most success if we keep our cycle tracks at street level.