Eyes on the Street: New Door-Zone Safety Space on Lake Street Bike Lane

IMG_2296.jpgExtra breathing room in the door zone on Lake Street. Photos: Michael Rhodes

Improvements to San Francisco’s bike network have been popping up all over town in the half-year since the city got partial relief from the bike injunction. Some of them are splashy — like the bright green, fully-separated bike lanes on Market Street, or the on-street bike parking stations on Valencia Street.

But the San Francisco Municipal Transportation Agency has been even busier with many small improvements and tweaks, including one or two changes that might not be subject to the injunction at all.

In April, when a portion of Lake Street got a touch-up in the form of a ‘Slurry Seal’ treatment (cracks and eroded areas were paved over without doing a full repave,) the SFMTA found a way to make biking a little safer. By narrowing the traffic lanes from 12 feet to 10 feet and adding the extra space to the parking lane, people on bikes now have extra breathing room between the door zone and moving traffic. The parking lane now stretches nine feet across, so cars no longer hug the edge of the bike lane.

"The San Francisco Bicycle Coalition is excited and pleased to see this re-striping on Lake Street," said the SFBC’s Andy Thornley. "It makes the already good Lake Street bike lane even better by reducing the danger of dooring, and otherwise makes the bike lane more comfortable and inviting."

Thornley praised the SFMTA for taking the initiative on the change, which involved no pushing from the SFBC.

"We encourage the MTA to make this improvement on every street as repaving occurs," Thornley added.

The Lake Street bike lane is already relatively wide at six feet, but
the added door-zone space makes it a lot less dicey. Not a shabby
upgrade for a repaving project that was already scheduled.

Have you spotted other small scale improvements to the bike network that almost escaped your notice at first, but have made a difference? Let us know in the comments section below.

IMG_2305.jpgA stretch of Lake Street where the bike lane hasn’t been re-striped and still hugs the parking lane.

  • This is a nice improvement indeed. Lake Street has some of the pleasantest stretches of bike lanes in the city, and this will upgrade them further. I do wish, however, we were creating buffered bikes lanes by putting the lanes between the curb and parked cars, like cities that are serious about bicycle infrastructure do. Ah well. Maybe the next repaving …

  • Winston

    While bike lanes between parked cars and the curb give a greater feeling of safety, accident statistics suggest that they’re more dangerous at intersections. This being said, the biggest factor that affects how safe cyclists are is how common they are, so if the lane is effective in encouraging cycling then it may improve overall safety. On the whole, I’d say that lanes separated from the road by parked cars are of questionable benefit at best.

  • Winston

    I should add that wider bike lanes moved out from the door zone are a very good idea.

  • Of course the best solution of all would be to create a network of completely separated bike paths like they do in most of Holland, but that is a little hard to do without closing down streets.

    Perhaps you could reference the studies that prove cycle track bike lanes decrease safety? I would suggest it is how the intersections are managed that is key. Check out this video of how Portland is doing it and how they very intelligently handle intersections:

    See also the bike lane protected by parked cars just approved in New York City:


  • Gillian Gillett

    We have 6′ wide bike lanes and a 8′ parking lane on San Jose/Guerrero. It’s lovely right up until there’s traffic. Since the average car is 6′ wide, a 6′ wide bike lane + parking lane cushion is pretty tempting for some motorists.

  • i’ll definitely take the improvement, and i, too, would like to see the parking flipped out to be next to other cars — though, I’m not crazy about riding my bike over bumpy concrete parking patches all day. and the steeper crown of the street on the edges might not be great for work bikes.

    i’d be curious to see a mockup of another option — instead of giving cars an additional two feet to play with (and be sloppy with), how about just create a 2-foot buffer between the bike lane and moving traffic?

    sure, we’d still have issues with the door zone, but we still have issues with the door zone in the current/new configuration, too — it’s just hopefully decreased a bit now.

    but if our goal is to get as many folks on bikes as possible, maybe offering better/more explicit separation from moving motor traffic might be more helpful than the decreased possibility of getting doored. ??

    here’s a diagram of having both in place at the same time.

  • This sort of bike lane separation sure would have saved me the two times I got doored.

  • Moley


    Yes it’s a great idea but unfortunately there are not many streets in SF that are wide enough to allow for this luxury.

    Lake Street happens to be one of them but I suspect the majority of streets like them are well out of downtown and so not where the bulk of cyclists travel anyway.

    Also bear in mind that the space has been taken away from the car lanes which, now being narrower, will cause more bumps and near-misses for the vehicles, and more opportunities for them to swerve into the bike lane.

    With road width at a premium, there is never a free lunch.

  • @taomom & winston:

    The main problem with putting the bike lanes outside the parking lanes in San Francisco is the high number of curb cuts. Drivers would be crossing the bike lane to pull into their driveways with visibility hindered by the parked cars. But Winston, I think they’re only dangerous at intersections if they lack visibility. They would need to remove the last few parking spots close to the corner (I think bulb-outs should be standard) and use colored paint to address that.

    I’m living in Denmark right now, and from the experience of riding them daily, I am telling you that they are definitely possible to make very, very safe.

    Tell me this has “questionable” safety: http://gis.aarhus.dk/kommuneatlas/gadebeskrivelser/Ny_Munkegade_1.jpg
    (This is in Aarhus, Denmark where I am.)


    “There are not many streets in SF that are wide enough to allow for this luxury.”

    Actually, San Francisco streets are very wide when you compare them to, say, European standards. But we give so much of it to parking & traffic. The truth is, we could remove parking lanes to create the safest, separated bike lanes possible, but people are used to them as the standard since the streets were designed as such.

    “Also bear in mind that the space has been taken away from the car lanes which, now being narrower, will cause more bumps and near-misses for the vehicles, and more opportunities for them to swerve into the bike lane.”

    From what I’ve learned, the traffic calming effect of narrower driving lanes outweighs and deters these potential risks.

  • Hi Aaron,

    With curb cuts and current bike lanes, you have the same problem when people back out from their garage/driveway. They must back out into the lane with visibility hindered by parked cars. People generally back out of their garages more slowly than they pull into them, but their visibility is even lower backing up than driving forward. Wherever the bike lane is located cars must use extreme caution when crossing them.

  • Tom Brown

    @Gillian and @winston

    The solution to cars using wide bike lines and poor visibility of bikes in separated lines is the same: more bikes! That might seem like catch 22, but help your friends get started with biking for transportation and enjoy the ride.
    No matter the state of the infrastructure it is probably a good idea to help newer riders be aware of the subtle risks of door zones and intersections. How that is received is a matter of timing and tone.

  • Moley


    It’s not realistic to expect to be able to get rid of significant amounts of private street parking. At least not without compensation since the US Constitution (which doesn’t apply in Denmark, I realize) disallows a Goverment “taking” without financial compensation.

  • Winston


    That facility definitely protects against the perceived risk of being hit by a passing vehicle from behind and is good in that it has no curb cuts. However the real risk is at intersections where bike paths increase accident rates.

    Taomom: there are a variety of studies. Shockingly the Wikipedia provides a good overview here: http://en.wikipedia.org/wiki/Segregated_cycle_facilities
    Especially look at the footnotes since they are a pretty good selection.

    Also, look here http://www.bikexprt.com/research/kaplan/specific.htm (which is a segment of a masters thesis) and scroll down to Location of Crash and Trip Purpose. This paper describes the U.S. situation as it existed in the 1970s.

  • Moley,
    You’re confusing constitutional protections with public policy. First, there is no “private street parking.” Parking spaces on the street are not private property, but public right of way. The government can decide how to use that without invoking anything from the constitution. It can be a bike lane just as easily as it can be parking.

    A “taking” or eminent domain is gov’t usurpation of private property, for which some compensation is usually required. Apples and oranges here.

  • Dave

    This article begs the question of why the MTA isn’t putting the bike lanes outside of the door zone everywhere there’s a bike lane. The Valencia Street bike lanes are notorious for encouraging people to ride in the door zone and for leading to injuries.

    The bike plan included some design suggestions to put cross marks in the door zone to indicate the hazardous part, sticking to a point about 10.5 feet from the curb. That would leave a mere 2-2.5. feet in most of the bike lanes, but we may as well be honest about that, and protect people from dooring (and increase the pressure for better designs, while we’re at it!) 🙂

    I generally like moving the bike lane to the other side of the parked cars, but not always and I don’t think it’s right for Lake Street: it’s pretty calm already, and it’s a low priority for the high expense of the design treatment(s) that would make it safe.

  • @Dave – what are these “Valencia Street Bike Lanes” of which you speak. I was riding Valencia today and it reminded me less of “Baghdad by the Bay” and more of the actual Baghdad 🙂

    It will be done sometime, but right now, man that’s a mess…

  • Nick

    Could they have installed a “double solid edgeline” on the left hand side of the bike lane? My opinion is that this should be the standard for all bike lanes in the city. 5 feet hugging the door zone is not good enough.

  • Winston,

    But I think the issue of visibility at intersections is addressed well if the parking is not allowed too close to the intersection. Take this example: http://maps.google.com/?ie=UTF8&hq=&hnear=Skejbyparken+12,+8200,+Aarhus+Municipality,+Denmark&ll=56.170411,10.20886&spn=0,0.002411&t=k&z=19&layer=c&cbll=56.170498,10.208904&panoid=wwSUL8HBCkyhh04xdotIHQ&cbp=12,149.27,,0,23.15

  • I find it mysterious that some bicyclists in the US and Britain—countries with incredibly poor bicycle participation rates and incredibly high fatality and injury rates–argue so extensively against segregated bicycling on the grounds that it’s less “safe” when countries that have successful bicycle cultures –Netherlands, Denmark and Germany—have achieved their success precisely through implementing vast amounts of physically separated bicycle paths and lanes. The Wikipedia entry referred to above is a perfect example of ostensibly neutral reporting that leans heavily on the side of keeping bicycles mixed with regular road traffic (probably because the author likes biking fast and feels comfortable there.) The article makes this case relying mostly on American and British “studies” rather than looking at what actually works in countries that actually do a lot of biking. It’s a pity the author of the article appears not to have read the excellent paper cited in the footnotes: “Making Cycling Irresistible: Lessons from the Netherlands, Denmark and Germany.”

    “The provision of separate cycling facilities is undoubtedly the cornerstone of Dutch, Danish and German policies to make cycling safe and attractive. They are designed to feel safe, comfortable and convenient for both young and old, for women as well as men, and for all levels of cycling ability. Separate facilities are not sufficient but they are certainly necessary to ensure that cycling is possible for a broad spectrum of the population. . .”

    “The most important approach to making cycling safe and convenient in Dutch,Danish and German cities is the provision of separate cycling facilities along heavily travelled roads and at intersections, combined with extensive traffic calming of residential neighbourhoods. Safe and relatively stress-free cycling routes are especially important for children, the elderly, women and for anyone with special needs due to any sort of disability. Providing such separate facilities to connect practical, utilitarian origins and destinations also promotes cycling for
    work, school and shopping trips, as opposed to the mainly recreational cycling in the USA, where most separate cycling facilities are along urban parks, rivers and lakes or in rural areas.”

    “As noted in this article, separate facilities are only part of the solution. Dutch,Danish and German cities reinforce the safety, convenience and attractiveness of excellent cycling rights of way with extensive bike parking, integration with public transport, comprehensive traffic education and training of both cyclists and motorists, and a wide range of promotional events intended to generate enthusiasm and wide public support for cycling.”

    If you download this excellent report (http://policy.rutgers.edu/faculty/pucher/irresistible.pdf) you’ll see photos of examples of infrastructure. In the Netherlands, this really does mean bikes are separate from cars—sometimes with parked cars as a buffer, sometimes with a grassy median, sometimes on a path that takes a completely different route from cars. They also pay careful attention to how they engineer intersections to reduce collisions between bicyclists and cars, and the resulting injury rate is extremely low. (Hint: far lower than the US rate.)

    To truly understand that one country knows what it’s doing with bicycles and the other does not, some statistics are in order:

    Percent of trips made by bicycle:
    US – 1% (San Francisco 3%?)
    Netherlands — 27% (Amsterdam 38%)
    Percent of bicycle trips made by women:
    Percent of children and teen trips made by bike:
    Percent of trips by people over 40 made by bike:
    Fatal injury rate per 100 million km cycled
    Nonfatal injury rate per 100 million km cycled
    (Note: low injury rate is not due to personal safety gear. Percentage of adult bicyclists in the Netherlands that wear helmets: less than 1%. Percentage of child bicyclists in the Netherlands that wear helmets: 3–5%)

    Sadly, British bicycling statistics are almost as abysmal as the US ones. If physically separated bike lanes are indeed more dangerous than riding in mixed traffic (as American and British studies purport to show), why have the Dutch, Danes and Germans adopted them so widely? Do they want to kill off their population? And if physically separated bike lanes bring death and destruction, why do those countries that have them have a fraction of the fatality and injury rates that we do? After all, we offer our bicyclists vast amounts of “safe” mixed traffic and some of the poorest excuses for bike lanes we can squeeze into a roadway.

    I suppose I should be grateful for all those arguing against separated bike lanes. Even though this lack of infrastructure makes it twenty-five times more likely I’ll be injured riding my bike and five times more likely I’ll die, still it’s all just “perceived” safety on my part really. “Real” safety is what “real” cyclists experience. Real cyclists don’t mind cars at their elbow, cars turning without signaling, cars pulling into or out of parking spots with no warning, or cars double-parking in the bike lanes. Real cyclists don’t mind taking the lane in 35mph traffic, love the roar of car engines, and are happy to breathe whatever particulate matter cars spew out of their tailpipes. If I would just get over my phobic notions of “perceived” safety, I wouldn’t find bicycling in San Francisco traffic stressful at all

    As I said before, Lake Street already has some of the nicest bike lanes in the city. If I were to choose to pilot bike lanes buffered by parked cars anywhere, I’d probably do it on Valencia or on The Three Blocks of Terror on Fell and Oak between Scott and Baker. But if a bikeway is not safe enough for a 10 year old to ride solo on, it is not safe enough. It’s that simple. And right now I know plenty of parents who live near Lake Street who would not think of letting their ten-year-old ride on those bike lanes due the adjacent car traffic. (And they are glad to tell you horror stories of just how bad Lake Street drivers can be.)

    When we have a network of physically separated bike lanes and radically calmed streets that allow children to ride their bikes to school with their parents’ blessing rather than be driven in a 5000lb SUV, then we’ll know we’ve done enough in the way of infrastructure. But until we get serious about reworking our infrastructure, calming our streets and reducing the dominance of cars, our modal share will remain in the single digits. If we want women, children and anyone over 40 (hint: the majority of the population) to bicycle in large numbers like they do in Denmark, Germany and the Netherlands, we need to take advantage of the thirty-five years of infrastructure experience those countries have and not keep arguing for our own chains.

  • Winston

    I think that a much bigger contributor to low car use and high bicycle use as well as the very low bicycle (and automobile) fatality rates in the Netherlands is that there are nearly no multi-lane high speed arterial roads there. In the netherlands roads seem to be either designed as expressways, freeways or 2 lane streets. There are very, very few streets like Oak in the Netherlands and streets like that have lots of auto, bicycle and pedestrian accidents. The problem isn’t the lack of segregated bike infrastructure per se. Rather the problem is that streets with uncontrolled access (i.e. driveways and parking) and multiple lanes are dangerous for all users.

    It gets challenging because all the ways to make such streets safe are fairly expensive. The cheapest approach for fell and oak would be to reduce them both to one lane each way. Of course doing so would drop the capacity of the pair of streets by about 2900 people/hour/dir (assuming an average vehicle occupancy of 1.2). To replace that capacity you would need to run buses – lots of them. Say a 60′ bus every 2 mins in each direction, so you would also need a bus lane. Unfortunately, the ROW is a bit cramped to support 2 way car traffic and 2 way bus traffic with good bike amenities. One possibility would be to construct one of the two roads with a 2 way busway and to narrow the other street. The other option that would fit would be a pair of 1 way busways on the two streets. The cost for such a conversion would be around $20 million for the street modifications plus about $3 million for the buses (and about 1.2 million/year to run the buses).

    Could it be done? Sure. Is there the political will to replace all the 4 lane arterial streets in SF with 2 lane ones and to add transit capacity to substitute? Probably not. Would increased bike use reduce the need for transit? Yes, but that bike use will be a result of slower car traffic more than of bike facilities.

  • Winston,

    I like all of that. And on your last point about slower car traffic, I think that’s really true, in addition to lower volumes of car traffic. The Danish city I’m in, Aarhus, is the second largest to Copenhagen, but it has half the rate of bicycle trips that CPH does. The biggest reason, I think, is there are more large, high speed roads to allow more car traffic, because the gap remains despite separated bike facilities on all those roads. Besides feeling more dangerous, it’s just plain unpleasant to ride near.


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