Archive for the ‘Traffic Signs’ Category

Children at Play (And at the Wheel)

My latest Slate column is up, examining the problems with “Children at Play” traffic signs (the headline, which is never the writer’s, may overstate things a bit…)

If the sign is so disliked by the profession charged with maintaining order and safety on our streets, why do we seem to see so many of them? In a word: Parents. Talk to a town engineer, and you’ll often get the sense it’s easier to put up a sign than to explain to local residents why the sign shouldn’t be put up. (This official notes that “Children at Play” signs are the second-most-common question he’s asked at town meetings.) Residents have also been known to put up their own signs, perhaps using the DIY instructions provided by eHow (which notes, in a baseless assertion typical of the whole discussion, that “Notifying these drivers there are children at play may reduce your child’s risk”). States and municipalities are also free to sanction their own signs (hence the rise of “autistic child” traffic signs).

Posted on Wednesday, May 18th, 2011 at 9:09 am by: Tom Vanderbilt
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And You Don’t Stop!

The stop sign column has occasioned a variety of interesting responses, including this visual piece from reader Tony which, needless to say, presents a mixed message.

Posted on Wednesday, May 26th, 2010 at 10:56 am by: Tom Vanderbilt
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Approaching Zero

After my post on the 14 mph speed limit sign in Orlando, reader Phil was moved to send in this photo, taken from a parking lot in Austin, Tx.

How low can we go? Anyone got a 2 mph? A one?

Posted on Thursday, May 20th, 2010 at 8:23 am by: Tom Vanderbilt
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14 MPH

In Orlando recently, out at a resort complex in the Disney-sphere, I saw a sign that caused me to do a bit of a double-take: 14 MPH.

I couldn’t recall ever having seen one of these before, though as the photo above — not the sign I saw — indicates, it’s not the only one.

Anyone know the origins of this peculiar sign? The 14 MPH seems like a weird translation from KPH, or is it intended to gain attention by sheer novelty? Does 14 represent some benchmark of safety above and beyond 15?

Also strange is that the sign was a rather normal suburban office-park/hotel complex like environment, with fairly wide, smooth streets — certainly not the kind that seemingly beg for a speed that’s actually hard to consistently track on a speedometer. In other words, if the powers that be wanted people going that speed, they’re going to need more than just that sign, however eye-catching. Needless to say, the taxi I was in was going more than that.

Posted on Monday, May 10th, 2010 at 12:12 pm by: Tom Vanderbilt
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Road Swill

Just in time for St. Patrick’s Day: Drunken pedestrian warning signs.

Alan of the Melbourne Urbanist sends along this link to the original Daily Telegraph dispatch; the sign is in Romania, but was apparently inspired by an unnamed town in Germany.

Interesting idea, though one wonders if the sign distracts drivers from the actual presence of sloshed revelers in the road; it also presume sobriety and attention on the part of the drivers themselves. “We must warn drivers that sometimes people who have little control over their actions can suddenly appear in the road,” the town’s mayor said. It’s just as appropriate to change the word ‘drivers’ to ‘pedestrians,’ to my mind.

Posted on Monday, March 15th, 2010 at 11:01 am by: Tom Vanderbilt
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MUTCD Addendum No. 214

(thanks Peter)

Posted on Thursday, February 11th, 2010 at 10:59 am by: Tom Vanderbilt
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Aesthetic Interchange

Reader Rich (sig?)-alerted me to this dispatch from Alissa Walker about an incredible piece of guerrilla wayfinding on the freeways of Los Angeles by artist Richard Ankrom, which lasted for the better part of a decade.

The curious denouement to the story is that the carefully pre-aged sign was taken down by CALTRANS, and then replaced with a “real” version. Ankrom was unable to locate his original, which has been turned into scrap metal destined for China.

Somehow this put me in mind of a recent line from Arthur Danto’s book on Andy Warhol, vis a vis the famous Brillo Boxes: “The challenge was to explain why Warhol’s box was art while its look-alike in common life was not.” (Danto thinks you cannot, hence pop art’s disruptive presence in the continuum of art history).

Perhaps it’s time for CALTRANS to institute an artist-in-residence program.

Posted on Monday, January 18th, 2010 at 2:06 pm by: Tom Vanderbilt
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Road Tautology

(thanks Dan Pink)

Posted on Thursday, November 19th, 2009 at 10:33 am by: Tom Vanderbilt
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Name That Sign

I got them all right — but you’d be somehow disappointed if I didn’t, right? Not that it was very difficult (though I will admit to taking a flyer on the “hazardous materials” entry). For a real run for your money have a go at the U.K.’s Highway Code (my favorite is the warning sign that says, simply, “ford”; hint, it’s not product placement).

(thanks Peter)

Posted on Tuesday, September 1st, 2009 at 8:36 pm by: Tom Vanderbilt
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Attention Please

This morning, I had read Eric Felten’s interesting take in the WSJ on the presence of hazards in places like the Grand Canyon, and why we shouldn’t install things like hand-rails, even on dangerous trails.

Then I came across, via Brainiac, a splendid website from the U.K. called “Attention Please” that chronicles warning sign overkill. Its stated mission:

This is a Manifesto Club photo-album, capturing unnecessary, absurd or patronising safety warnings in public spaces. By turning our cameras on needless safety tape and signage, we hope to expose those who put them there – and encourage a more rational approach.

One of their gripes, vis a vis the Grand Canyon:

Even in our national parks and areas of outstanding natural beauty there are up to 45 signs per mile, destroying any feeling of wilderness or tranquility.

Posted on Friday, August 28th, 2009 at 12:32 pm by: Tom Vanderbilt
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Snow Job

Reader Pat sends along a photo he snapped of the old Glenn Highway near Anchorage, Alaska. In case you can’t make it out, the sign after the avalanche warning notes “School Bus Stop Ahead.”

Posted on Wednesday, August 26th, 2009 at 7:40 am by: Tom Vanderbilt
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Your Speed

Reader Jay sends in a link to this interesting take on the traditional “your speed is” feedback signs (“speed trailers” as they are sometimes called). From what information I can find they seem to be the work of the ad agency Cramer-Krasselt, possibly for the Wisconsin town of Elm Grove, but I’m not sure if it’s a print PSA or if these signs have actually appeared on the side of the road. Has anyone actually seen them?

Posted on Monday, August 3rd, 2009 at 6:54 am by: Tom Vanderbilt
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More on Emotionally Intellignent Signage

Sign nuts: Don’t miss Daniel Pink’s pecha-kuchka presentation on “emotionally intelligent” signage, as referenced in the previous post.

Posted on Friday, June 5th, 2009 at 2:49 pm by: Tom Vanderbilt
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Of Flying Monkeys and DIY Traffic Signs

Reader Shasha sends in this great example of merging property rights with some home-made driver beahvior modification. Considered it entered in the new MUTCD — the Manual of Unofficial Traffic Calming Devices.

Shasha’s rationale was as follows:

We live on a small and relatively quiet road. The speed limit on our road should be 40 (curves, narrow, and hills). However, like all county roads in our county, the speed limit is 55. This means that people actually attempt to go 55 or faster.

I have spoken with our local authorities about putting up signs that state “Slow, Children at Play.” It seems that those signs are no longer legal to use, as it indicates that children have permission to play in the road. Hmmmm.

So, I decided to put up signs on my own land. I figure if they are funny and memorable, people may think and slow down. Or, if nothing else, they will slow down simply to see the signs. This sign (Watch for Flying Monkeys) comes from a picture I took of SuperS who was swinging from a rope in the front of our house. Yes, he appeared like a monkey. I thought it would be perfect. With a little design magic, I created a sign and posted one on each side of the road — as people approach our house / driveway.

I’m not sure it’s emotionally intelligent signage however, as it asks us to have empathy for flying monkeys, a creature few of us have seen.

Posted on Friday, June 5th, 2009 at 2:40 pm by: Tom Vanderbilt
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‘Speed Zone Ahead’ and Other Types of Road Ambiguity

I enjoyed this post from Jeff Sommar on the ambiguity inherent in “Speed Zone Ahead” and other road signs. About “Speed Zone,” he writes: “Reading it at face value, which when you think about it, is how street signs should be read, you would think that the sign is alerting you to the fact that you will be able to speed up in the zone ahead.”

He goes on to mention the sign is used to signal increased speed ahead, as well as decreased speed, which I don’t think is actually true (please confirm, any engineers). But his point about the vagueness is well taken. The sign, after all, doesn’t tell you how much the speed is dropping by (or exactly when). As it turns out, the engineers have heard his cry of confusion, and the sign as pictured above is on the way out, according to some chatter on the MUTCD websites (this site shows some of the new configurations, which are yellow rather than white, and state specific decreases — never increases — in speed). As a side note, there’s also some discussion about what the proper placement is of these signs — so drivers have sufficient time to react and slow before hitting a new speed zone and, perhaps, a speed trap.

The “Speed Zone Ahead” sign brings up another issue of mine, which is the problem of having a road marked for, say, 65 mph, which suddenly hits a stretch that is 35 mph — but the road is exactly the same. The “Speed Zone Ahead” sign is thus a rather weak signal in changing behavior. I think compliance would be higher if, for example, the road were made narrower in the slower section; some alternative paving treatments were introduced; another potential solution is “optical speed zones,” the subject of an article in the latest ITE Journal by Steven Latoski — this treatment uses “bars” painted across the road that diminish in proximity as the driver progresses across them, thus increasing the feeling of speed, thus targeting “an instinctive road user reaction of relaxing the accelerator or adjusting the cruise control.”

I also like Jeff’s mention of the “Dangerous Intersection” sign. Given that signalized intersections account for a very high percentage of traffic crashes, perhaps this should be placed at all intersections. I understand the impulse to put up the sign, at least to provide liability coverage; but is that really all that can be done? And does putting the sign up at one location cause one to lower one’s guard at other areas not so marked? Tricky stuff, this traffic engineering.

Anyone else have favorite examples of signs that gave them pause? My favorite is one that says, simply, “No Traffic Signs.”

Posted on Sunday, March 29th, 2009 at 6:41 pm by: Tom Vanderbilt
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When Is a Stop Sign Not a Stop Sign

Reading this post about a law to allow cyclists to treat stop signs as a yield, something that invariably tends to raise ire among drivers (and some cyclists), reminded me of this post from a while ago — the video embedded there reminds us of the small fact that many drivers (at least in Kansas) already tend to treat “Stop” sign as a yield (at best).

And, in case you haven’t read it, after the jump I’ve posted the classic article (from Access magazine) by physicist Joel Fajans and Melanie Curry, “Why Cyclists Hate Stop Signs.”

(Horn honk to Richard)


Posted on Tuesday, February 10th, 2009 at 1:54 pm by: Tom Vanderbilt
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I Respect Your Right to Drive Like a Maniac Down This Street, But…

Since so many drivers seem to lack any other kind, Needham, Massachusetts is hoping to appeal to their “emotional intelligence,” reports the Boston Globe.

As is so often the case, the community in question is trying to get people to drive more slowly on neighborhood streets with schools and children. The typical signage seems to do squat. As the story notes, “The idea is that seeing a child’s handwriting and drawing will make parents relate to the sign in a way they never would with an impersonal version.” In other words, it’s not the voice of the impersonal state, but a child — and how many SUVs loaded with parents’ own offspring are barreling down that road?

Interestingly, this idea did not stem from traffic engineers. Writs the Globe: “She said the novel approach came out of a conference she attended last year, when Daniel Pink, best-selling author of “A Whole New Mind,” talked about using so-called right-brain skills like empathy to communicate more effectively – and ultimately to be more successful.”

Pink himself “came upon the idea by accident while visiting a New York museum with his wife and three young children. The family took a break from touring to get something to eat at the museum cafeteria. ‘The line is just outrageously long,’ Pink recalled. ‘And I’m all stressed out about that because we don’t have a lot of time, and I don’t want to waste my time at this beautiful museum waiting for a grilled cheese sandwich.” Then he saw a sign that read, “Don’t worry. This line moves really quickly.’ Pink said he immediately felt much calmer and it made his entire experience at the museum better.’

This may all be a bit too soft for the New Yorker raised on “Don’t Even THINK of Parking Here” and its ilk. And I’m not sure about the legibility of those signs (then again, legibility is only half the issue). But I’m all for unconventional approaches, and this one seems an interesting parallel with the U.K.’s “road witch” trials and David Engwicht’s “intrigue and uncertainty” ethos, the idea that the “outdoor living room” of a residential street, one that shows signs of life, might be as or more effective than anonymous, disregarded signs. I’m also not sure about the ‘novelty effect,’ but in any case it will be interesting to see how it plays out (the town is trying the ’empathetic’ signage for other purposes, as well). I like the idea of simply posting images of huge sets of eyes with any traffic message, as psychological experiments have shown how eye contact (not necessarily “real” eye contact) improves cooperation.

Part of me can’t help but to look at those “child-like” signs, meant to engender feelings of empathy for the nearby children, and think they almost say more about the drivers. We often hear about how children are “unpredictable” and do things like cross at inappropriate moments, but to look at the behavior of drivers through these school areas it is they who seem to be behaving without the appropriate amount of control and risk-awareness. How can a person drive in such an environment without the understanding that they are in the presence of unpredictability? (of course, with issues of speed, one tends to only hear from drivers about how they feel they are traveling at a speed that is safe for them, without taking into account the ethical dimension of how their behavior raises the risks to others). To take the analogy further, how many “children” do we see out on the roads, hostile to being reigned in, thinking that parental rules don’t apply to them, selfish to the extreme (swap a toddler’s crying for the horn), angry when their toys are taken away (how dare you remove parking spots!).

What do y’all think — more carrot, less stick? Or the reverse? Or a whole new way of thinking about the problem?

Posted on Tuesday, February 10th, 2009 at 10:13 am by: Tom Vanderbilt
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Don’t Fear the Raptor

I’ve seen signs on small churches in the South that warned the Rapture was coming, but I’ve not yet seen a “Raptors ahead” warning.

What began with Texas zombies, then moved to Nazi zombies, has apparently become a nationwide phenomenon, with Indiana drivers being warned of some unseen hawk presence.

“It’s kind of crazy. I’m totally confused,” said one motorist. “I’m kind of expecting … dinosaurs to run down the road, or something.”

Well, defensive driving lesson number one is: Expect the unexpected.

Posted on Thursday, February 5th, 2009 at 7:58 am by: Tom Vanderbilt
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Non-compliant Signage

Posted on Friday, January 30th, 2009 at 4:56 pm by: Tom Vanderbilt
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The Hidden Benefits of HOV Lanes

HOV, or “carpool” lanes, are, like everything, the subject of much controversy in the world of traffic. Do they make congestion worse for everyone while only aiding a few? Do they cause more crashes? Needless to say, I could have written a book only on the complexities of the Diamond Lanes (though I’m not sure who would want to read it).

A new paper, “The Smoothing Effect on Freeway Bottlenecks: Experimental Verification and Theoretical Implications,” from Michael J. Cassidy, Kitae Jung, and Carlos F. Daganzo at the University of California-Berkeley, presented at last week’s TRB (I’ll be data-mining the huge trove of research from that conference over the coming weeks), suggests that HOV lanes can provide overall benefits to highway traffic flow — even when the lane itself is underutilized. As with many things about traffic flow, this is beyond the grasp of the average driver, who may simply look over at the HOV lane, see that fewer cars are in it than his own (even if, of course, they’re carrying more people), and begin to grouse about misguided government policy.

The authors looked at a particular stretch of California freeway with a regularly occurring bottleneck, essentially a “merge bottleneck” resulting from increased volumes of entering traffic. A carpool lane becomes active during the morning and evening rushes; and one might be led to think the activation of the lane somehow causes the bottleneck. But the authors note, “previous analysis established that the carpool lane did not contribute to the bottleneck formation and capacity drop. Instead, and as is typical of merge bottlenecks without carpool lanes, the queue first formed in the shoulder lane and then spread to all lanes.” But even as the capacity of the carpool lane began to drop, the researchers observed an interesting pattern: The “discharge” of vehicles from the bottleneck in other lanes actually began to increase.

They looked at video footage, taken from a pedestrian overpass, to figure out what was going on. Interestingly, it was all about changing lanes. In lane 2, as pictured above (the one next to the HOV), drivers made fewer changes in and out of it when the carpool lane was activated (some of those drivers may have previously been jumping back and forth between lane 1, the ‘fast lane,’ and 2).

And here’s where it gets really interesting:

The same phenomenon was observed a few minutes earlier in lane 3, as drivers started
anticipating the impending carpool restriction. The video data reveal that: (i) drivers’ tendencies to avoid the median (carpool) lane as its activation time approached created crowded conditions in adjacent lane 2, starting at about 14:52 hrs; and (ii) although this crowding temporarily induced some drivers to migrate to lane 3, its more significant impact was to dampen the entries made into lane 2 from lane 3; (see Cassidy, et al, 2008). The net result: lane-changing maneuvers between lanes 2 and 3 diminished at 14:52 hrs, as revealed by the boldfaced oblique cumulative curve in Fig. 5. As in the case of lane 2, this reduction in lane changing was accompanied by a sudden and sustained increase in lane 3’s discharge flow.

The authors observed what they called a “smoothing effect.” Drivers were less tempted to change lanes, because there were fewer options available, and the “discharge flows” actually increased. When the carpool lane wasn’t activated, lanes saw anywhere from 9% to 13% worse performance in VPH (vehicles per hour). When considered in terms of “people hours traveled,” the activation of the carpool lane provided a benefit on the order of 30%. The authors note that if this “smoothing effect” is not observed and quantified, long highway delays might be incorrectly attributed to the carpool lane.

What’s interesting about this is that for many of those individual drivers, they were presumably changing lanes to try and improve their own position. But in doing so they were actually reducing the overall performance of the highway.

As the authors note, it’s worth investigating how signage and striping might reduce “disruptive” lane changing. “Disruptive lane changing,” they add, “might also be reduced in some cases by sorting drivers (and vehicle classes) across lanes according to their preferred travel speeds; or in other cases by inducing a more even distribution of flows across lanes.”) We already have seen “variable speed limits” to help smooth out flow in a linear sense; maybe someday we’ll have “variable lane assignment” to smooth it out across the highway.

Posted on Monday, January 19th, 2009 at 11:24 am by: Tom Vanderbilt
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Traffic Tom Vanderbilt

How We Drive is the companion blog to Tom Vanderbilt’s New York Times bestselling book, Traffic: Why We Drive the Way We Do (and What It Says About Us), published by Alfred A. Knopf in the U.S. and Canada, Penguin in the U.K, and in languages other than English by a number of other fine publishers worldwide.

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