Urban Tribe - Ride with your kids in front.

In London, ’20’s plenty’ fast enough

Posted by on September 1st, 2010 at 9:14 am

Sounds reasonable to me.

Streetfilms has a new video on 20’s Plenty for us, a campaign in the U.K. working to make 20 mph the standard speed limit in residential areas. The campaign is catching on quickly, with more and more U.K. cities adopting the policy all the time. Given that PBOT might be considering a legislative fix to wrest greater control of speed limits from ODOT, and the fact that Mayor Sam Adams has already shown an interest in reducing speed limits and has made safety his number one transportation priority, this could be an idea that catches on here in Portland.

The 20’s plenty pitch is simple: Lower speeds make for more pleasant places to live, work, and play. Seems like everyone would agree to that. Watch the excellent video to hear how people working on the campaign pitch the idea:

A 20 mph speed limit isn’t just fodder for a catchy campaign slogan, its impact on saving lives has been confirmed by major study findings and even the World Health Organization has endorsed 20 mph speed limits. (Learn more about London’s success with 20 mph zones in this Streetsblog article.)

PBOT has used the “Effects of speed on stopping distance” chart (see it below) in neighborhood meetings and presentations for at least five years now (I first published it in 2005). It shows that 20 mph is the maximum speed at which someone can operate a motor vehicle and still stop in time to avoid hitting someone…

Effects of Speed on Stopping Distance
View full size
(Chart: PBOT)

The Streetfilms piece also reminded me of a law that passed in 2007 but that I’ve not heard much about since (thanks to reader Robin Dale for bringing it to my attention again). In the 2007 legislative session, State Rep. Carolyn Tomei sponsored a bill (H.B. 2297) that defined a “narrow residential roadway” as any street “not more than 18 feet wide at any point between two intersections or between an intersection and the end of the roadway” and “Not of sufficient width to allow one lane of traffic in each direction.” The bill amended Oregon’s basic speed rule so that all such roadways could have a maximum speed limit of just 15 mph. Unfortunately, it seems that there aren’t many streets that fit that bill and it seems to have had little impact thus far.

Here in Portland, most residential streets have a 25 mph speed limit and many streets which run through highly residential areas (like N. Rosa Parks Way for instance) have speed limits of 35 mph.

One way I can imagine PBOT approaching new speed limit laws and policies is to legally leverage the “neighborhood greenway” concept. Neighborhood greenways are PBOT’s new name for bike boulevards, which are “family-friendly,” residential streets where people on bicycles and on foot are prioritized. Similar to how Rep. Tomei was able to define “narrow residential roadway,” PBOT could define neighborhood greenway in the ORS and then attach a 20 mph speed limit to it in Oregon’s basic speed rule. Then, any street officially classified as a neighborhood greenway would automatically have a 20 mph speed limit.

Lower speed limits — when coupled with smart engineering, focused enforcement, and a bit of marketing — would do wonders in helping create residential streets where everyone feels safe and welcome.

— Read more of BikePortland’s coverage of this topic by browsing our “speed” story tag.

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  • PdxMark September 1, 2010 at 9:25 am

    One benefit of the very narrow neighborhood streets of inner east Portland is that even 20 mph is hard to maintain in any reasonable way. The wider residential streets in many suburban towns invite faster driving. It just goes to show how roadway desin affects liveability.

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  • Steve B. September 1, 2010 at 9:33 am

    There is a 20mph zone as you reach the end of the 405 southbound offramp into downtown. It’s impressive to see this on such a wide street, just off of a highway.

    How’d we do that? An appeal to ODOT?

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  • Joe Rowe September 1, 2010 at 10:02 am

    My post and another post were just deleted.

    Joe, no they weren’t. You posted a comment on the “Speed Kills” story from 10/05. Did you mean for it to post here intead? — Jonathan.

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  • Joe Rowe September 1, 2010 at 10:24 am

    Good to hear that the majority of a dense city can start to accept that fast cars are the real terrorists likely to harm your loved ones.

    Portland residents and city leaders have yet to accept slower speeds and a tiny bit less parking.

    Safety is related to speed, but another hidden factor is parked cars that block views near crosswalks. I’d love to see a story on that.

    Both legal and illegal parking causes some near misses in front of my house. When I asked for help, PDOT’s response was to quote the law that the pedestrian has the duty to not step out in front of cars. But what if the ped is a kid, or someone who can’t retreat if a car speeds around these blind curves?

    PS: Sorry to Jonathan. I posted to the wrong story.

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  • Steve September 1, 2010 at 10:36 am

    Wouldn’t they be looking at 20 kph (13.6 mph)?

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  • Vinny September 1, 2010 at 10:36 am

    @ Steve B. #2

    Downtown Portland has a statutory 20 mph speed limit because it is a business district. That’s a state statute. There are just not a lot of speed limit signs. I’d like to see 20 mph signs at the I-405 exit ramps as drivers enter downtown.

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  • Steve September 1, 2010 at 10:42 am

    Oh yeah, English system actually from England…Duh. Back under my rock.

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  • 9watts September 1, 2010 at 10:42 am

    Portland also has a little known ‘skinny streets ordinance’ which even folks at the City I’ve talked to don’t know about.

    And from a book “Streets and the Shaping of Towns and Cities” comes this quote: “Portland, Oregon is one of the few cities in the United states that is actively pursuing and changing their street standards. The Skinny Streets Program has been vigorously implemented in both established communities and new ones since 1991. [really?] By reducing local residential street with by as much as 12 feet (3.6m), skinny streets have become a cost effective way to preserve livability and neighborhood integrity. Most streets are designed to be no more than 20 to 26 feet (6-8m) wide depending on neighborhood parking needs.” (p. 134)

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  • Whyat September 1, 2010 at 10:45 am

    I’m not trying to create flames but 20pmh really is ridiculously slow. It’s hard to drive that slow. I routinely reach speeds of 25 and 30pmh on my bike. Let’s look at realistic speeds of 25-30. No one is going to drive 20mph on a big wide street, and it’s my guess that it wouldn’t be enforced. The majority of accidents are caused by inattention, and not speed.

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  • Anton September 1, 2010 at 10:48 am

    On the Autostrade of Italy, they post stopping times according to your speed and visibility ranges according to the weather. Very cool.

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  • are September 1, 2010 at 11:05 am

    if you routinely reach 25 to 30 on your bike on residential streets you are going too fast for conditions.

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  • Amos September 1, 2010 at 11:15 am

    “…20pmh really is ridiculously slow. It’s hard to drive that slow.”

    Hard? Don’t be silly. You’re operating a machine with the light touch of your feet and hands. How hard is it really?

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  • 9watts September 1, 2010 at 11:22 am

    “20pmh really is ridiculously slow”
    Of course it is. It also casts doubt on the major promise of owning a car–that you can and deserve to go faster than everyone else. But that doesn’t mean it isn’t good for children and other living things.
    Germany has been moving toward reducing speed limits within towns from 50 km/h to 30 km/h (31 to 19 mph) since the 1980s. See
    “Die Einführung von Tempo 30 in Nebenstraßen ist vielerorts zu einer Routineangelegenheit geworden und Tempo-30-Zonen sind im Bewusstsein der Bevölkerung fest verankert. Mit Rücksicht auf die angrenzenden Nutzungen und die Verkehrssicherheit in empfindlichen Abschnitten von Hauptverkehrsstraßen sollte auch hier häufiger die zulässige Geschwindigkeit auf 30 km/h begrenzt werden.”

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  • 9watts September 1, 2010 at 11:29 am

    I meant to translate that last bit of German:
    “The introduction of Tempo 30 on side streets has become commonplace in many towns, and Tempo-30-zones have become firmly rooted in popular consciousness. Taking adjacent uses and traffic safety along sensitive portions of arterials into consideration, 30 km/h should be the speed limit here as well.”

    FWIW, this is taken from the website of the German Ministry of Environment

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  • mabsf September 1, 2010 at 11:51 am

    As an inhabitant of a street near to a school with many kids I think 20mph is more than enough! Only problem: WHO is going to enforce it?
    I see people speeding through my street all day long…
    It seem like it would be such a money-maker for our police force!

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  • Merckxrider September 1, 2010 at 11:57 am

    I live in a semi-rural suburban neighborhood with very few sidewalks–30kph is a good speed for that setting.
    I also drive a car with a sort of dual-mode transmission–an automatic that can work in a sort of phony manual. The semi-manual, like a real manual shift, makes it much easier to not speed on residential streets.

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  • middle of the road guy September 1, 2010 at 12:28 pm

    what a dumb idea.

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  • 9watts September 1, 2010 at 12:30 pm

    probably not so dumb if you’re in the middle of the road, eh?

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  • spare_wheel September 1, 2010 at 12:31 pm

    “Of course it is. It also casts doubt on the major promise of owning a car”

    It would also make it easier to take the lane since most fit cyclists can maintain 20 mph!

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  • spare_wheel September 1, 2010 at 12:32 pm

    “what a dumb idea”

    thats exactly what i think when i see single occupancy vehicles lined up in traffic.

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  • timbo September 1, 2010 at 1:09 pm

    Reducing ALL city street speeds by 5 miles per hour would do amazing things for bike ridership. Both for safety and reducing the time gap between car vs. bike.

    Do I take a car? Or should I just ride my bike?

    Slower cars make the differential much smaller.

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  • A.K. September 1, 2010 at 1:09 pm

    It’s not hard to drive 20 MPH, it’s just hard to not want to speed up to what feels like an “acceptable speed” that you are used to, especially when you have another vehicle tailgating you because they are impatient as well.

    Sure, it “feels” relatively slow to go 20 MPH, especially when you have just exited a faster area, but the kinds of streets that 20 MPH is acceptable for shouldn’t be used for distance driving. Get back out of the neighborhood and onto a faster arterial if you really need to go more than 20 MPH.

    “The majority of accidents are caused by inattention, and not speed.”

    These two are linked in a car, though. If people are driving slower, the driver would have more time to react to a sudden situation (once they removed their head from their arse and started paying attention), which would lower accident rates.

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  • Spiffy September 1, 2010 at 1:15 pm

    Lower speeds make for more pleasant places to live, work, and play.

    unfortunately, Americans want to get from where they live to where they work/play as fast as they can in a car… trying to restrict their speed and make it take longer for them to get somewhere is not going to attract voters…

    but I’m sure politicians can put some kind of positive spin on it… and then the media will wipe it all out with some sensational story about the city taking away our ability to get where we need on time…

    I went from a car to a bike… so for me it was a reduction from 45mph to 15mph… so to go from 35mph to 20mph shouldn’t be that tough… but selfish people will fight it to the end…

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  • Merckxrider September 1, 2010 at 2:57 pm

    Merckxrider, your comment was deleted because it contained an offensive insult. Please refrain from doing that in the future. Thanks. — Jonathan

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  • 9watts September 1, 2010 at 3:14 pm

    You’re not far off the mark, Merckxrider. We’ve done it before:

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  • Kevin Wagoner September 1, 2010 at 8:17 pm

    I would love to see a reduction in speed limits. A speed zone around the green zone would make this a better place to live.

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  • Zaphod September 1, 2010 at 10:05 pm

    My vote is for 15 mph on residential streets. Not arterial residential (like NE 15th, 21st, Knott) but those in between. If you navigate properly then your travel time will be impacted by less than 30 seconds on the outside.

    One should drive very gently on streets where families, pets & kids are often present. Society has collectively been drinking the car-centric kool-aid for far too long.

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  • SkidMark September 2, 2010 at 1:13 am

    Stopping distance depends on how far away the driver SEES someone in the road, how fast they react(brake), and the distance it takes for them to stop. It’s not so much a matter of speed as it is paying attention and having a good reaction time.

    Personally, I would prefer raising the speed limits 5 mph across the board. Newer cars can stop faster with their ABS and large power-assisted disc brakes. If cars could travel faster they would be to their destinations and off the road sooner. The drivers would not zone out as much from driving soooooooo slow. They would be less frustrated because it wouldn’t take a ridiculous amount of time to travel from one place to another.

    You are not going to bully people out of their cars by making them drive slower. They will just resent cyclists even more for making them drive even slower.

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  • Natty September 2, 2010 at 5:14 am


    While the modern braking systems may be able to stop a vehicle in a shorter distance, the reactionary delay of the driver has not improved and higher speeds of travel on residential streets will only exasperate the least efficient link in the system.

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  • Merckxrider September 2, 2010 at 9:00 am

    9watts, that’s what I’m talkin about!

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  • wsbob September 2, 2010 at 11:47 am

    Reduced speeds is a good idea…20mph limits are a good idea. In addition to the extraordinary danger they pose to people nearby on foot and bike, fast moving cars make a huge amount of wind and tire noise that can seriously degrade the areas they travel through.

    It’s not that hard to keep the motor vehicle at 20mph or even 15mph. For people that think this is something they won’t be able to to manually, a lot of cars today have cruise control.

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  • GlowBoy September 2, 2010 at 12:59 pm

    I would guess the reaction time of the average driver has increased in recent years with all the distractions that now seem to be considered acceptable.

    20mph is not that hard. If you have a “hard” time maintaining 20 (for example, in a school zone or downtown), then you either have an overpowered car or an overpowered foot. Learn some self control before you kill.

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  • peejay September 2, 2010 at 1:29 pm

    Most modern cars are designed to operate smoothly and vibration free well in excess of the maximum highway speeds, which just encourages people to drive faster, because the car provides no negative feedback loop to the driver for excessive speed. A car designed for safety would rattle and shake the faster it was driven, to discourage speeding. But, unless required by legislation, such a car would remain unsold, while all the overpowered, overstabilized cars flew off the dealers lots. And the drivers of those overengineered cars would complain how it hurts their motor to go so slow.

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  • SkidMark September 3, 2010 at 11:35 am

    I really don’t understand why Oregonians are so afraid of driving fast. Maybe it’s because you never never get the opportunity to so therefore never learned how.

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  • Opie September 4, 2010 at 1:06 am

    Even though many cities in the UK are ‘catching on’ to the ’20’s Plenty’ movement, it’s not as smooth a transition as it seems. Here in Glasgow we have many crowded residential streets with ’20’s Plenty’ signage, and yet the majority of motorists disregard and speed away while children walk to school. While Portland is by no means the perfect city, it is better than most. I’m hesitant to get on board with comparing the UK’s preference for low-speeds to the Portland Metro’s preference for all things bicycling. I’ve been living in the UK for about a year now, and I feel compelled to say that this is quite possibly the worst country in ‘Europe’ to ride a bike. A bit of an exaggeration, yes. In Scotland, more specifically Glasgow, the roads are in terrible shape, and as I mentioned before, by and large people disregard speed-limit signage. On my street (an apartment-lined street), drivers regularly drive upwards of 40mph. Bike lanes here, while in ample supply, are not well-maintained (the paint is barely visible) and cars regularly park in them. On top of all this is the seemingly low-number of traffic cops in the city who are ill-equipped to deal with the amount of blatant disregard for traffic safety.

    On the front of ’20’s Plenty’ at home, I believe that if your commute is seriously hindered by driving on streets that are posted at 20mph, you might consider re-evaluating how you get to work, or school for that matter. I admit, as a driver, forcing one’s self to drive at such a low-speed is most annoying. I think the underlying reason why ‘we’ get so frustrated is that a car is designed for higher-speed travel. It’s hard to push this thought to the back of one’s mind when forced to obey such low-speeds inside a heap of metal. I would compare this to getting all kitted up in road-riding gear just to spin an easy 8mph. Did I really need the lycra?

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  • Brian Tang September 4, 2010 at 6:06 am

    London campaign = 20 kph (~15 mph).

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  • Lee Colleton July 26, 2017 at 10:37 am

    That WHO press release is available through the Internet Archive (original link is 404: not found) https://web.archive.org/web/20100301163020/http://www.euro.who.int/mediacentre/PR/2004/20040406_2

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