Which is better for bike lanes: concrete curbs or plastic posts?
In the small, fast-growing world of the protected bike lane, Seattle is the city of physical beauty.
I won’t lie to you: my organization, which helps U.S. cities build protected bike lanes, named Seattle’s rebuilt Linden Avenue as our No. 5 project of the year because I saw it in a video on the Internet and developed a crush on its little gray curbs.
New York uses parked cars. Chicago uses plastic posts. But with the neat, subtle concrete curbs and gutters of Linden and Broadway, Seattle has been bringing a European sense of permanence and durability to its protected bike lane projects.
Don’t get used to it.
Like most of the other U.S. cities that are following in New York’s and Chicago’s footsteps, Seattle is about to embrace the plastic white bollard.
If it doesn’t, City Traffic Engineer Dongho Chang said in an interview, you can kiss your expectations for a fast-growing network of protected bikeways goodbye. (That, or dramatically increase your budget for new bike infrastructure. Your call.)
It’s not just because cast-in-place curbs are expensive compared to other bike infrastructure, though they are: about $250,000 per mile for the curb alone, according to the latest estimates from Austin bikeway engineer Nathan Wilkes, compared to $120,000 for posts and paint. (Other expenses, such as dedicated traffic signals at large crossings, add to the pricetag as well.) It’s also because of the Americans with Disabilities Act, which requires all street corners adjacent to road “reconstruction” projects to be fitted with wheelchair-and-cane-friendly curb ramps for $11,000 a pop.
If Seattle retrofits a street with an attractive Broadway or Linden-style curb, it triggers ADA upgrades. The cost to fix all those curb ramps: another $375,000 a mile or more, Chang says. The Broadway and Linden bike lanes were parts of larger street reconstruction projects, so the ADA work would have happened with or without the bike lanes. But for streets that are not otherwise being reconstructed, installing curbs with bike lanes could trigger the ADA improvements.
So Seattle will likely set out to avoid such costs if possible by avoiding bike lane designs that would also trigger sidewalk upgrades.
“My takeaway is that a lot of these protected bike facilities, if we can do it low-cost to start out with, tend to be easier to put in,” Chang said. “Buffered bike lanes with the flexible posts: very easy. They don’t require any drainage, and if you they have good pavement, then you don’t have to trigger the curb ramps.”
The federal rule regarding when to upgrade sidewalk curb ramps isn’t just constricting Seattle’s options on bike infrastructure. It’s radically increasing the cost of crosswalk upgrades, too.
“If you have a remarking of crosswalks, that’s maintenance, but if you’re putting in a new crosswalk, that’s reconstruction,” Chang said in an interview recently. “When you’re doing a patch across the crosswalk, that’s maintenance, but … if half of crosswalk area is redone because of potholes, then that’s reconstruction and you have to redo the curb ramps.”
In other words, a high-visibilty zebra crosswalk that might usually cost about $250 costs $22,000 at a corner with bad curbs.
For bike lanes installed with plastic posts, Chang said the city would plan to replace the posts with curbs — and, presumably, upgrade the necessary ramps — at some point in the future.
Mike Amsden, Chicago’s top bike project manager, said his city, too, is taking a two-phased approach: posts now, curbs eventually.
Amsden said in an interview that though he has “a little bit of envy” for cities such as Austin and Seattle that have started with curbs, he’s more or less happy with Chicago’s decision to build most of its projects with bollards.
“There’s pros and cons to doing it both ways — quality versus quantity, honestly,” Amsden said. “The philosophy of just getting as much in as quickly as you can is great.”
Amsden said Chicago has found that each mile of bollards seems to require about $1,000 per year in maintenance. At that rate, it’d take more than 100 years for a concrete curb to pay for itself in maintenance savings alone.
On the other hand, Amsden said, curbs add value that flexible posts don’t.
“They create kind of a sense of place,” Amsden said. “Which goes a long way to selling these projects to people who may not care about bikes.”
Michael Andersen is the staff writer for the Green Lane Project, a PeopleForBikes effort to promote better bike lanes in cities across the U.S.
56 responses to “Andersen: Using plastic posts instead of curbs, Seattle plans to reduce the cost of protected bike lanes”
I would much prefer the use of bollards and have a wider network of protected bike lanes vs. fewer protected bike lanes and curbs. I think this is a good decision.
The only way I would support the use of the plastic posts extensively is that they *get replaced* immediately when run over by motor vehicles. Case in point: Dexter/7th/Denny. The former plastic posts were completely obliterated 3x before SDOT gave up on replacing them, was without any sort of ‘protection’ for months and months, not even paint, then finally replaced them with a Cement Curb.
The posts really don’t do much more for bike lanes/boulevards than paint when a car/truck hits them. And, to me, inspires more fear when I see those posts laying down after being run over repeatedly.
Ok, correction: I rode by the Dexter/7th/Denny area last night. They are just the plastic posts. And more than half of them have already been destroyed after installation in the fall. No replacements to date. The posts have a larger base that looks like it’s cement but they are not. And it doesn’t provide much of a barrier at all for cyclists, especially once the posts are all run over.
At least they hit something before they hit me, even if it’s a plastic post.
The idea of all these features is to get more people on bikes and to insure as much safety for all road users as possible. If plastic bollards do not result in these outcomes, than the money is pretty wasted regardless. I’m interested in knowing whether there is any research behind either facility in terms of ridership numbers and safety. A connected bike network is absolutely the end goal and spending our limited resources wisely to build as much as we can as quickly as we can should be part of the analysis. However, from a resource and political standpoint, if we build it and people don’t use it, that’s even worse than not building the facilities at all.
Sorry, but tailoring construction projects to avoid ADA upgrades is the wrong attitude for the head of a city Department of Transportation to have. In my opinion it doesn’t meet the standard of care that a professional like Mr. Chang should exhibit towards his constituents.
I like post. No curbs please. Nothing like a crowded bike lane with grandma on a three wheeler going 1 mile an hour and now way to pass safely with a stream of on coming bicyclist. One day that will be on the three wheeler with my dog in the basket holding up all those young people trying to get where they are going.
The curb is on the outside. Are you saying that you are unable to pass over the dotted line?
I think bikealot is saying (and if not then allow me to…) that the focus on “all ages and abilities” for bike infrastructure can put a lot of slow and erratically rolling obstacles in the way of some cyclists who want to travel faster, and giving them the option of temporarily leaving the bikeway between the bollards is preferable to crossing the dotted line into a potential head-on collision with the slow and erratic or fast and direct opposite direction bike traffic or to obliquely bunny-hopping the curb.
If the separated lane is wide enough, you can easily pass. There are usually enough gaps in the oncoming bike traffic as well as driveways in which you can leave the separated lane at.
So, from my experience with Vancouver’s separated lanes, it’s not a problem in practise.
As a bicyclist I find those curb cuts to be helpful as well. What’s nuts is the cost of the curb cut, what magic material are they using that makes them so expensive?
Exactly. And the $11k quoted is *per* ramp, and is the best-case scenario cost.
We applied for curb ramps at some intersections for the 39th Ave NE Greenway. We figured at $10k a ramp, we could cover 4 corners (2 ramps per corner, at 2 intersections, on one side of the street only) for the cost of the grant (around $75k; in theory, there are small discounts for multiple curb ramp installations).
Nope. After winning the grant and some SDOT studies, it turns out that the intersections needed regrading in order to be ADA-compliant. That meant a higher price per corner. After the study, it looks like that $75k will get us 4 ramps total. That’s nearly $20k per ramp!
I agree with Dongho’s logic; given the ridiculous cost of curb ramps, it makes sense to try and avoid curb ramp work. If I were focusing only on bicycle infrastructure, I would come to the same conclusion. However, people *need* those curb ramps. It’s not just people in wheelchairs – it’s also parents with strollers, senior citizens with walkers, toddlers who’ve just begun walking, kids on balance bikes, people pushing shopping carts, and so on. The long-term solution here isn’t bollards (though they’re a short-term one), the long-term solution is to fix the absolutely ridiculous cost of curb ramps.
They’re not this expensive in other cities!
I keep wondering if SDOT could just start using these all over until serious road work is being done at an intersection.
http://www.grainger.com/product/22RR22 ($160, and no drainage concerns).
Since they extend out into the street, they’d also form a bit of a curb extension. Extra traffic calming ftw.
The city thinks that if they install temporary infrastructure now, they can take it back from us later.
I ride Linden most mornings. Between 143rd and 138th the cycle path is “protected” by paint and plastic posts; the rest is curb. Of the 36 cars parked between 134rd and 138th this morning, all but 8 of them encroached on the cycle path. That is significantly better than the typical morning – usually all but one or two of them are parked over the line. This morning the guys at the builder’s supply place were late – they were parked next to the cycle path but they weren’t unloading in it.
These issues do not exist in the sections with curbs.
Well, I’ve already seen what happens with the plastic bollards. Cars drive over them. Broadway @ E Denny for an example. And calling street/sign repair to have it fixed is an exercise. Evidently the term “bollard” is an unfamiliar term so you have to be very specific what you’re reporting so that SDOT knows what you are reporting.
maybe they could put spikes or flames to the bollards just lessen the appeal of running them over
They’re probably confused because what you’re reporting isn’t a bollard.
A bollard is a rigid fixed or hinged post strong enough to physically prevent vehicle entry, typically steel or concrete, sometimes with a wood wrap.
What’s shown here are delineators, not bollards.
A delineator is a flexible, reflectorized, plastic post designed to rebound when hit by cyclists or vehicles. Very different piece of infrastructure if you’re actually familiar with the terminology, so if you report a missing bollard, they’ll look on the plans and see there aren’t supposed to be any bollards there.
I only used the terminology “bollard” because that’s what I heard them referred to as.
Didn’t mean to sound critical, just provide terminology that will help get repairs under way.
Good point, Josh. I’m no engineer but I agree that there should be a langauge distinction between hard posts and soft ones. “Bollard” is a term I’ve heard frequently from experts for both, but I do like the usage you suggest.
The bollard/delineator distinction is standard engineering speak, it matches what they’re used to internally, in design standards, etc.
Also, if you happen to have a cell phone with a decent camera, emailing a photo of a problem to [email protected] always gets me a competent response — it shows exactly what the problem is, even if you don’t know the right engineering speak for it.
Ugh, the plastic bollards are not a good solution. Just like paint, they get destroyed so fast and then we are left with drivers encroaching on the bike lane to park/unload/whatever. We should spend the extra to do it right. And ADA compliance shouldn’t even be a discussion point. ADA passed 30+ years ago, we need to make things compliant faster. And it shouldn’t come out of bicycle improvement budgets.
That’s the key point right there. The bike plan’s “cost” includes a ton of these ADA improvements. I think the city absolutely should invest in more curb cuts. Being the most accessible city would be an awesome goal.
But if those costs get conflated with “bike costs,” the political momentum for bike lanes could be hurt. After all, $1.5 million for a mile of protected bike lane definitely sounds like a hell of a lot of money. But when you realize you are making the entire street more walking-friendly and dramatically improving accessibility, then the price tag starts to make more sense.
As for safety, both bollards and curbs are largely symbolic, neither will actually stop a car moving fast enough to cause a serious collision. And neither one protects people on bikes where they’re most at risk, in intersections.
Why are the choices limited to curb or bollards? There’s a bunch of other options shown here — I particularly like the planters they use in Vancouver.
+1 for planters!
I know the planters can get pricey, too. I wonder if they would trigger the ADA requirement and how they compare to a cement curb. Good question! I’ll see if I can find out.
Planters are a crash hazard if they don’t have suitable clearance and conspicuity.
They also need more right-of-way than a simple curb or line of delineators, they need reflective hazard markings, the plantings require maintenance, and if the planter is tall enough to reduce the pitch-over hazard for cyclists, it’s tall enough to obstruct sight-lines.
Hitting those curbs a glancing blow can topple you right into traffic. It’s not much fun having some Stravacide squeeze you into the curb as he passes willy-nilly.
And street lights hurt when you crash headlong into the pole but that doesn’t mean we should do away with them..
Jayne, does that mean your comment two minutes later regarding the yellow rubbery textured curb-cut material was meant to be humorous irony?
I agree with Sarah, making glancing contact with a low concrete curb very well could topple you directly under the wheels of adjacent motor traffic, and it seems a far too likely consequence of curbed two-way cycle ways. I don’t mean to overstate the inherent dangers of two-way cycleways, but I do feel they’re glossed over far too regularly here.
Curbs and street lights serve a purpose, the yellow mats do not (unless you include funding whatever politician’s brother’s yellow mat factory as a purpose, I do not). Although I applaud your cleverness, since the internet is so bereft of anonymous gripers trying to play gotcha (there’s the humorous irony you were looking for).
Well, we don’t know (and Tom does ask the question above your comment in the thread, so I’m confident in saying we don’t know…) whether the mats serve some purpose, I’m merely pointing out that you’re awfully quick to brush aside the safety concerns of some (hitting the curbs) calling for elimination of one grade separation form factor (said curbs) with your streetlight pole strawman, and yet nearly simultaneously ready to outlaw another piece of infrastructure (yellow mats).
It just seemed a little like Carrol’s Queen of Hearts (Off with their heads!)
but at the heart of it we’re on the same side here: Cycling should be as safe as possible (unless you want us to hit the light poles…) we just have different ideas about how to best effect that aim.
Jayne – Those yellow mats serve a very important purpose – to tell visually impaired people where the edge of the road is. Prior to ramps, blind individuals were able to tell the difference between sidewalk and road due to the curb. However, with the ramp, it was very difficult to determine where the road began and the sidewalk ended. The truncated domes helped that distinction due to the pattern and size.
The color is directly related to the contrast between the sidewalk and the ramp. While yellow is a default color in most jurisdictions, others have chosen white, black, brick or other colors. The main factor is the contrast ratio between the sidewalk/ramp and the domes.
But we do install light poles in compliance with mandatory minimum setbacks from traffic.
Curbs are safe enough next to bicycle facilities if they’re properly installed as the potential hazards they are, with the required shy distance for vertical obstructions, conspicuity markings, etc., and if the path they protect is wide enough to safely allow overtaking cargo bikes, wheelchairs, tandems, trailers, etc.
Unfortunately, SDOT has a habit of undershooting minimum bike facility widths to begin with, and often does not provide the required shy distance for intrusions into bicycle facilities. (That’s true of both curbs and plastic delineators — just look at the posts on Cherry, for example.)
Slightly off-topic, but I’m not thrilled with the yellow rubbery surface that the city has been installing on curb ramps. Even though they appear to be designed for traction with a dotted texture, I have found them to be surprisingly slippery for bike tires when wet. Could the city save money and improve safety by ditching the yellow mats and returning to the old textured concrete ramps? What was wrong with those? Maybe some regulation required the switch to the rubbery mats . . .
That’s a good question. I know why the texture is there (ADA requirement for visually-impaired to know where the sidewalk meets the street), but I’m not sure why the plastic/rubber mats are used instead of a textured cement option. Many are bright colors, so maybe the color is important as a visual cue? Anyone know?
DC has a lot of ramps with textured cement and it looks much nicer than our yellow plastic.
Tom – Some agencies tried to produce concrete ramps with the truncated domes in them. There were issues with consistency in meeting the ADA standards. Also, maintenance was difficult because the concrete would chip off and not meet ADA standards. The truncated dome tiles/mats are easy to use and install in ramps which is why they are the most common application.
Curb cuts aren’t designed for bikes, they’re primarily specified for pedestrians and wheelchairs.
The standard slip-resistance test used for truncated domes simulates a shoe slipping out, not a narrow, high-pressure tire.
The size of the domes is intended to let blind pedestrians feel the presence of the domes through the soles of their shoes.
The bright color is for visually-impaired, but not totally-blind, users, to make it easier to identify the curb cut or other feature.
FYI, if you think the rubberized domes are slippery, try steel tactile pavers in areas that have to worry about snow-plow resistance!
Thanks, Mike and Josh, for the added details on the rubber textured mats.
Yes. Thanks for the explanations of the mats’ purpose in assisting the visually impaired. Recognizing that bicycles are not the primary users of the ramps, I still wonder if there is a different material or design that would be less slick while still offering comparable tactile and visual assistance to the visually impaired. Like most slippery surfaces, there no problem when going straight up the slope, but going at an angle or turning (as when merging into the traffic lane), I find the mats to be surprisingly slick.
Bikes aren’t usually the primary users of the ramps with yellow textured pads… but there will be more and more places where they are as more bike routes include elements at sidewalk level. Check out Yesler near Broadway for an example. And, of course, some of Seattle’s most popular bike routes include bridge crossings on sidewalks, so I guess we have to assume that at some time in the future all the ramps serving those routes will require similar elements to be ADA compliant?
Manufacturers are continuing to develop new materials for these tiles. There are some preformed, skid-resistant, fiber-reinforced cement versions on the market, supposed to be durable enough where they aren’t exposed to heavy equipment or hard winter freezes.
I would hope SDOT periodically reviews its standard specifications to stay abreast of improvements in the technology.
Agreed, those yellow things are awful. They should be illegal.
I would actually prefer 3 miles of well thought out, physically separated cycletracks, than 30 miles of poorly thought out cycletracks separated only by plastic posts. Much like I prefer 3 miles of real bike lanes to 30 miles of sharrows.
I have an idea, put those spiked strips between the plastic bollards so if they hit them they also have to hang around with a couple of flat tires until the police arrive and give them a bill for the replacement price.
Bollards are a great short-term solution, but they will not be as effective as a cold, hard curb.
Imagine if we took this attitude with sidewalks. “Well, a raised concrete area to walk is too expensive, let’s put plastic tubes in the road and let people walk on the shoulder.”
Emergency fix? yes. Quick implementation? Yes. Long term solution designed to increase the comfort and attractiveness of bicycling? No.
I actually wish they’d do this in NE Seattle, where plenty of places north of NE 75th lack sidewalks. I’m not aware of any budget or plans for finally installing them. Heck, Lake City’s planned greenway is going to be on a street without sidewalks.
One thing that is worth pointing out, btw – these plastic bollards, much like curbs, are not meant to stop a car* when it hits it. You can read lots of stories in the past year where someone driving a car jumped a sidewalk curb and killed a pedestrian, for example. They’re mean to provide a signal to drivers that a section of the right-of-way is off limits to them, and also to slow them down. A narrower roadway will cause a driver to subconsciously go slower. The main difference between bollards and concrete curbs in this regard is asthetics, and durability. If it’s cheaper to do bollards/delineators and replace them yearly for 20 years than to do a concrete curb with a 20 year lifespan (20 years is a guess), then I’m all for the bollards/delineators.
* Well, maybe the Jersey barrier on the NE 65th cycletrack can stop a car, but everyone hates how ugly it looks. :)
[…] pros and cons to doing it both ways — quality versus quantity, honestly,” Amsden told Seattle Bike Blog in January. “The philosophy of just getting as much in as quickly as you can is […]
[…] is how all this work was done on a $200,000 budget (that might sound like a lot, but it’s very cheap in terms of transportation […]
[…] explore this issue in a new guest post for Seattle Bike Blog, the first of a round of guest posts we’ll be doing for other websites that can help spread […]
[…] pros and cons to doing it both ways ? quality versus quantity, honestly,” Amsden told Seattle Bike Blog in January. “The philosophy of just getting as much in as quickly as you can is […]
[…] pros and cons to doing it both ways — quality versus quantity, honestly,” Amsden told Seattle Bike Blog in January. “The philosophy of just getting as much in as quickly as you can is […]