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SDOT compares road diets to Copernicus’ struggle for heliocentric acceptance

Road diets efficiently move people and goods while dramatically reducing collisions, particularly collisions that cause injuries. We know this. Study after study supports it from all corners of Seattle and from cities around the globe.

Yet every time they are proposed, they bring controversy. Once SDOT explains the studies and research behind the decision to redesign a road with excess capacity (often a four-lane highway style design) to one with one lane in each direction and often a center turn lane, some people simply do not believe them. Some say the city’s crazy, that it is somehow attacking people driving (by making it so they have fewer collisions?) and that there will be gridlock. Nothing SDOT says seems to satisfy the concerns.

And yet, each time such projects are completed, studies come back showing that they worked exactly as SDOT said they would: Traffic volumes remain the same, collisions go down and injuries go way down. Often, bicycle volumes go through the roof and more safe crosswalks are installed.

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But the fact that SDOT’s recent redesign of Fauntleroy Way once again worked as predicted is not likely to prevent doom criers from spreading fear next time a similar project is proposed. I’m not talking about worried residents, whose fear of gridlock near their homes is understandable (and for whom the city’s outreach should improve, though that would cost money). I’m talking about voices in the media who will paint such projects as a bike project or another “attack” in the city’s “war on cars” conspiracy theory (Clearly these studies are made up to further the city’s nefarious goal of annoying drivers. “Safety” is obviously a smokescreen to justify the city’s ultimate goal of taking away your car).

In a recent post on the SDOT Blog, the department compares road diets to Copernicus struggling to gain acceptance for the idea that the earth revolves around the sun. A messy metaphor, perhaps, but their point is that road diets are counter intuitive. Though it may seem odd or even obviously wrong that three lanes can move traffic as efficiently as four, the science is clear.

Road diets work really well, and they’re really cheap. In a tight budget, road diets are more important than ever.

From the SDOT Blog:

The radio story made me wonder if SDOT staff might feel a little bit like Copernicus when they present a project to the public that, to some people, seems to defy common sense.

Lately SDOT has been doing some road reconfiguration projects, where we reduce the number of lanes in each direction from two lanes to one, usually add a left turn lane and sometimes add bike lanes.  When some folks hear about these projects, they feel strongly that it’s just common sense that having fewer travel lanes will mean more backups and congestion.  That argument seems as solid as the terra firma under our feet, right?

But the thing is, SDOT engineers only recommend these changes after doing their research and confirming that the data show that traffic levels are low enough for a reconfiguration to work.

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23 responses to “SDOT compares road diets to Copernicus’ struggle for heliocentric acceptance”

  1. Rob H.

    Results have been stellar for my local road diet on Greenwood Ave. N., south of N. 105th St. I’ve found benefits as a driver, pedestrian, dog walker, bus rider and bicyclist. All I can say is keep it up, SDOT, eventually folks will wonder what the fuss was about.

  2. Karena

    I think one of the problems is the horrible branding. Whoever thought up “road diet” needs to be tarred, feathered, and run out of town. The term immediately brings up negative associations–after all, who likes being on a diet? So of course a road diet will be something unpleasant that makes your life worse. Unfortunately, “road diet” is short and snappy, something that other attempts at branding lack: “traffic flow and safety optimization road modification?” I don’t think so.

    As part of turning around public opinion and educating people about the benefits of a “road diet,” we need a new term, and it should come from the question “what do people like?” Perhaps “rainbows, unicorns, and free ice cream road upgrade?” Perhaps not. But I’ll take it over “road diet.”

    1. Tom Fucoloro

      The name has gone through lots of versions. The city prefers “rechannelization,” which is pretty good. It’s a straight forward description. I also like “redesign” because it’s the same idea, but less weird sounding.

      The term road diet is just what many cities around the world have called it for a long time. This Streetfilm has more on the history of the road diet, a term coined in 1996: http://www.streetfilms.org/mba-road-diet/

      I don’t mind the term, but it definitely brings potential emotional baggage with it. After all, diet to me sounds like eating the correct amount to be healthy (so a road diet is a design that provides the correct amount of road for healthy traffic flow). But if you tortured yourself for years on the Atkins diet, living in fear of bread crumbs, then you probably have a negative reaction to the word diet.

      I also once tried to get the term “road tailoring” to catch on. Our roads are like over-sized pants that need to be brought in so they fit better for the traffic that exists. But nobody bit.

      But no matter what we do, road diet is the term that’s going to stick around in discourse. If we try to disown it, the term will just be co-opted by opponents to the projects. Like so many debates, it seems safe streets is often a battle of linguistics (and we’re not doing so hot).

  3. Doug Bostrom

    “Road modernization” works better for me. We’ve got decades of data telling us how roadways actually work, we no longer have to guess first and then build. It’s time to use that data and modernize our transport infrastructure.

    We don’t miss the Sperry Univac and all its myriad vacuum tubes, except as a subject of misty nostalgia. We moved on to smaller, more efficient replacements and have found them to be quite delightful, as predicted. How’s that for a tortured metaphor?

    1. Tom Fucoloro

      Agreed. I really like the term “modernization.” A four-lane highway design through the heart of neighborhood is a dinosaur of traffic engineering, especially when traffic volumes are nowhere close to needing that much roadway. We know better and have better tools today than when these roads were designed this way.

      I dream of the day 23rd Ave by my house in the CD is “modernized.” Today, it might as well be a fortified wall dividing the neighborhood. For only $50,000-$100,000 per mile, we can reconnect the neighborhood and dramatically improve safety at the same time. That’s an incredible deal.

      1. merlin

        Yes!! Can’t wait for 23rd to be modernized/rechannelized/dieted!! I cross it every day to get to work, usually on foot walking my bike – and maybe 1 of 500 drivers recognizes that I exist, and of those, 1 of 50 yields the right of way. And none of them are driving the speed limit.

  4. Jonathan

    I just drove on the road dieted section of 125th and I’m scratching my head a bit here… not only did I not see any cyclists it looks like a much steeper hill than I would attempt myself unless there are no better options. On the other hand, traffic didn’t seem terribly impeded by the redesign so I agree with that side of the argument.

    Personally I would prefer to see money spent on improving trails rather than sharrows, which in a lot of these areas like Lake City seem like a wasted effort.

    1. Tom Fucoloro

      NE 125th was not really a bike project. It was a traffic safety project aimed primarily at creating safe pedestrian crossings and reducing the high numbers of injury-causing collisions that were happening. It also happens to be the only street for quite a few blocks on either side that actually continues through the neighborhood. Yes, it’s hilly and yes, people who are just passing through might find a completely different route to take. But for anyone who lives or works in the surrounding neighborhood to bike anywhere, NE 125th is pretty much the only option.

      1. Eric

        I agree that this is a great safety improvement. I used to live up there, and had many close calls both on my bike and in my car, all involving cars turning left or cars speeding in the opposite curb lane when I was turning left. A friend of mine even got her car totalled by a left turning car who didn’t see her because of traffic in the inner lane. I agree about the hill (at least westbound). However, the street grid layout in that area is very car-centered, and 125th is the only through street.

    2. Shane Phillips

      Tom basically covered it in his response, but it sounds like you’re falling into the trap of labeling these road diets as bicycle projects. Bicycle access was probably just about the last thing they thought of on this project.

      Increasing safety always comes first, so changing from 4 lanes to one in each direction with a middle turn lane was probably the first consideration. After that you’ve got extra space and paint certainly isn’t expensive, so why not give some space for bicyclists as well (especially when the route is the only option for many riders)?

      I’d also like to see money spent on trails, but the fact of the matter is that this rechannelization was happening regardless – mainly to improve safety – so painting a few extra stripes or sharrows is a pretty negligible cost for a very clear benefit to bicyclists, even if there aren’t yet that many of them.

      1. Sharrows have some major benefits over trails. First, the places people want to go are along roads. Trails are usually placed wherever there’s extra land, which is usually not where people want to go. Second, every new trail opened in this town is a demonstration of our outright incompetence at designing intersections for them. Sharrows are drawn on public roads, which mostly have acceptable intersection design.

        My experience is that in Seattle drivers tend to respect me (and my right to take the lane as necessary) more where there are sharrows, especially where those sharrows are drawn in wise lane positions (at least out of the door zone).

  5. Gary

    The biggest valid complaint I’ve read about roads being reduced from 4 lanes to 2 with a center turn lane is for right turning traffic is often blocked by pedestrians. Instead of having a lane to go around these blocking cars, everybody behind waits and fumes.

    Of course the fix is a dedicated right turn lane but that has it’s own problems for bicyclists who now must cross that lane to go straight.

    1. Doug Bostrom

      That’s where the old saw “patience is a virtue” comes in. Behind the wheel is completely the wrong place for impatience.

      Keep the four lanes and the right turn delay will be diminished, but vehicles turning left will then frequently cause other vehicles behind to have to do lane changes, leading to brake applications for other vehicles farther back as well as affording an opportunity for an accident (every lane change is a chance to have an accident due to divided attention).

      It’s also pretty much axiomatic even if somewhat counterintuitive that the faster one attempts to travel on streets with mixed traffic, the more often one ends up coming to a complete halt or being forced to violently change speed or make poorly planned lane changes, all of these behaviors being diagnostic of poor driving skills.

      1. Todd

        Patience? Patience?? That’s were the axiom distance equals rate multiplied by time comes (d=rt) in — but most Americans are stupid and failed math. Because if they hadn’t, they’d realize going 50 mph verses 30 mph for their typical 5 mile trip or less isn’t going to make any significant difference in the time they arrive at their destination. We can’t expect patience or logic here. Expect dumbasses and devise a system for impatient dumbasses.

      2. Shane Phillips


        I think that’s the point of the rechannelizations: it takes lack of patience out of the equation. Now you have no choice but to do the safe thing and wait for traffic to resume, rather than trying to swerve around the car in front of you, potentially cutting off or sideswiping another car, or hitting a pedestrian or bicyclist who the guy in front of you was stopped for.

    2. Compare to 50th through the U District, where there are two lanes going through in each direction. Drivers going through end up weaving around stacks of cars waiting to turn, which occupy alternating lanes as 50th crosses alternating one-way streets.

      Cyclists *always* have to cross right-turning traffic to go straight through an intersection in a certain sense. The way to do it right is to have the right-turn lane merge with the bike lane (or across it if there’s room) to create a pocket for right turns; the left edge of the bike lane should remain straight, but become dotted. This uses the standard language of lanes on the road to communicate behavior, and allows for an orderly and predictable traffic flow. Really, you can almost dispense entirely with markings near intersections. NE 65th has really minimal markings and people get it right. Fremont Ave in Fremont (especially going downhill) is similar.

  6. Eric

    If anyone is trying to re-brand the idea, it might be a good idea to de-emphasize what is being removed (a through lane in each direction) and emphasize what is being added (left turn lane, crosswalks, other safety improvements). Also probably a good idea to make clear that the two inefficient lanes are being replaced by one efficient lane, and capacity will not be reduced. “Road diet” makes it sound like you’re giving something up. In these projects, road users are actually getting something, not giving something up.

    1. Tom Fucoloro

      Talking about urban space sure is complicated.

      Good points.

  7. One thing SDOT could do is ask residents to drive on a street that’s already been road-dieted, preferably one they drove on before the road diet.

    However, I suspect even if SDOT could convince people of the benefits of road diets, they’d still be opposed. The fact that no one cares that more people are killed in car accidents than any other cause shows that no one cares about road safety. All drivers care about is “I won’t be able to go fast anymore” and they will not be happy.

    1. Tom Fucoloro

      I disagree. “Drivers” don’t like dying or being injured anymore than anyone else. It’s just that we’ve gone all this time thinking that a certain amount of death and injury must be accepted for the sake of traffic flow, and people don’t immediately trust that the city would make changes to improve safety for all (rather, they see it as pandering to people biking).

      People don’t like driving, and therefore don’t like plans that MIGHT make them be in their cars more than they already are. We need to do a better job explaining how much less stressful it is to drive on a “dieted” road than a four-lane neighborhood highway. You have fewer high-stress moments, fewer risky movements are required, and fewer slit decisions to make. Everyone has a little more elbow room, and everyone keeps moving.

      Perhaps this is where a good video from a driving (or multiple) perspectives would be useful…

  8. Clark in Vancouver

    What worked eventually for most people understanding that the Earth is not flat is education. Your view of the world is that it is flat but because you’re educated, you’re shown that the larger view is that it’s round and the flatness is just how it looks locally.
    So in this case, people need to be educated to the larger view. How traffic works, comparisons with other places, etc.

    Also, is there any way for the citizens to collaborate with their government to get things done and not have the media find out and ruin things?

  9. mike archambault

    Does anyone know if the city has thought about approving a “package” of rechannizations? Maybe discussing 5 or 6 projects at once would limit the unnecessarily repetitive grief and cost that all parties encounter in debating them as individual projects.

  10. Jon

    I wonder if the SDOT messaging about such projects would be aided by also highlighting all of the locations where their studies do NOT recommend rechannelization? I’m sure the studies are available, but are they effectively pointed to as examples of what criteria are used in the decision-making?
    The ‘package’ idea is a good one, too. Combine the two (the ‘rechannelization package’, and the ‘leave-alone package’) into a single message and it may preempt some push-back.

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