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Friday, July 5, 2013

The Pseudo Problem-Solving of Traffic Engineering

Posted by on Fri, Jul 5, 2013 at 9:29 AM

When ever I see one of these dumb devices (this one is on the corner of Pine and Boren)...


I recall this passage from Jane Jacob's last book, Dark Age Ahead:
Given this enviable professional background [of engineers in general], plus the extreme tendency of North Americans to admire scientific achievement and give it the benefit of the doubt, it is little wonder that traffic engineers have been trusted to do pretty much as they please, and that departments of public works have gratefully accepted and followed their recommendations for design and specifications of streets and roads.

In what traffic engineers have chosen to do and have recommended, they have abandoned and betrayed science as it is understood. "Engineering" also has an opprobrious connotation of manipulation without regard for truth, as in "engineering consensus," or "It looked spontaneous, but it was engineered." It is popularly assumed that when universities give science degrees in traffic engineering, as they do, they are recognizing aboveboard expert knowledge. But they aren't. They are perpetrating a fraud upon students and upon the public when they award credentials in this supposed expertise.

Considering the current state of things, we can say with the certainty that we know the earth is older than 6000 years, that traffic engineers are only good at keeping themselves employed. Outside of that, they do nothing but dig a city deeper and deeper into the abyss of the negative city, the satanic urban. If we are going to get the city we want, we need to do as Jane Jacobs did and furiously attack this profession, file its sharp teeth down to nothing, and make it into a sheep rather than the lion of urban planning. For a traffic engineer to be at all useful to a city, he/she has to be committed to the destruction of his/her profession.


Comments (41) RSS

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Bus riders used to wait no longer than 45 seconds to turn left at Elliott and Mercer on their way from Ballard to downtown.

Now they can wait as long as 4.5 minutes.

Because SDOT did some "engineering".
Posted by d.p. on July 5, 2013 at 10:05 AM · Report this
Lew Siffer 2
Bus bulbs, "traffic calming"', turning 3 lane roads into 2, indeed Charles.
Posted by Lew Siffer on July 5, 2013 at 10:13 AM · Report this
Fnarf 3
I think a better approach would be to get the traffic engineers on our side. As long as we have streets, we're going to have traffic engineers. Pretty hard to run traffic lights without them. But someday the traffic engineers will START by thinking of multiple modes, not just shoehorning peds and bikes into a car world.

@1, is there a city number you can call for this, like there is for potholes? I know a few lights that are ridiculously timed too. And the lights on Aurora, which were synced with great fanfare some time back (Nickels? Schell?) are reverse-synced now, meaning it is impossible to drive down the street without hitting red on every single one of them, unless you're going 75 mph.
Posted by Fnarf on July 5, 2013 at 10:15 AM · Report this
Ernie1 4
I'm curious, what is this "city that we want" supposed to look like? For starters, it won't be taller than 3-4 stories without engineering. Bridges probably won't work out that well either.
Posted by Ernie1 on July 5, 2013 at 10:22 AM · Report this
Ernie1 5
Oh, traffic engineers, poor reading comprehension got the best of me.

Anyway good luck with that.
Posted by Ernie1 on July 5, 2013 at 10:25 AM · Report this
Dr_Awesome 6
Charles, re you and Jane Jacobs:

Bullshit, bullshit, bullshit, bullshit, bullshit.

Mega-epic troll, Charles. And good Friday morning to you too. Good goddamn, that is some stupid stuff in that passage you quote. I guess it's just easier to criticize something without ever bothering to understand how it works or take any time to learn how it works.

For what it's worth Charles (and everyone else) within the last decade traffic engineers HAVE been working to learn, understand, model, and improve all modes of transportation- cars, buses, bicycles, pedestrians, light (and heavy) rail, and others.

For example, the models for traffic used to consider only vehicle delay as the standard measure for congestion. Now all delay- whether single-occupant vehicle, multi-occupant vehicle, bicycle, or pedestrian- are being considered.

And- as in any other field, there exist differing opinions among all the engineers. There is no one best answer, and no one concrete interpretation of any certain principle when it comes to putting in the pavement. It is a science, but like all the other sciences the variables are so numerous in its application that it is not and never will be applied perfectly to the satisfaction of everyone.

Next consider the body politic. The epic bullshit quote from that bullshit Jane Jacobs passage is "...traffic engineers have been trusted to do as they please."

Did I mention, Charles, that that is bullshit? You are stupid for believing it, Charles. Stupid.

Nothing a traffic engineer does is without scrutiny from the body politic in some way. Nothing. And you want to talk about a body that does not have any scientific training, nor any engineering training, nor, more importantly, an understanding of the principles of traffic engineering? It's the body politic, the body that, often as not, re-directs, re-designs, dumbs down, or outright rejects the plans of the traffic engineers.

Traffic engineers have not abandoned science. You are stupid for repeating that, Charles. Stupid. Traffic engineering is an ever-evolving and growing science. As I noted above, it is learning to consider, plan for, and design to things that were not often considered a generation ago.

But good trollery this morning, Charles. You got me all worked up via that bullshit you posted. Good work.
Posted by Dr_Awesome on July 5, 2013 at 10:35 AM · Report this
The pedestrian countdown timers on the Burke Gilman Trail in Lake Forest Park have a ridiculously long countdown on them - longer than the 'walk' phase and far longer than it actually takes cyclists and runners who most frequently use that trail to clear the intersection.

What happens is very few users of the BKT actually follow the law and stop when the countdow phase begins - it's illegal to enter a crosswalk during the countdown phase - and the local cops then hassle trail users for not following an arbitrily-set rule that does nothing to enhance safety.

One has to wonder the degree to which traffic engineers are complicit by ignoring science (using empirical evidence about how long it takes the average trail user to cross 20 feet of roadway) and instead simply setting the timers to whatever interval the cops or city council wants.
Posted by SuperSteve on July 5, 2013 at 10:38 AM · Report this
I'm reminded of how George Will goes on about how environmental science isn't really science.
Posted by GermanSausage on July 5, 2013 at 10:39 AM · Report this
@3, talking sense to SDOT has been tried, to no avail. Someone there is convinced that the world will end if outbound Elliott isn't treated as an freeway from 2pm to 8pm. Even though the bottlenecks have simply relocated further up the road.
Posted by d.p. on July 5, 2013 at 10:42 AM · Report this
Your ideas are intriguing to me and I wish to subscribe to your newsletter.
Posted by bunkzilla on July 5, 2013 at 10:46 AM · Report this
Matt from Denver 11
I would bet that many of the timing issues that you folks are complaining about are the result of political decisions, rather than implementing recommendations based upon the findings of the traffic engineers. I have no proof, but the final decisions are typically made by the appointees who head traffic departments.
Posted by Matt from Denver on July 5, 2013 at 10:51 AM · Report this
Dr_Awesome 12
@7 The pedestrian phase (the total time of the WALK and the Flashing-Don't-Walk/Countdown) is set for the slowest pedestrian, which is normally an elderly person walking at or under 3.5 feet-per-second. That's why the walk phase seems so short- you do not ever want a person walking that slow to run out of time to clear an intersection.

It is against the law (for the traffic engineer), and can be fatal (for the pedestrian).

That's not to say that the timing can not be adjusted to improve things. Newer signal controllers have a whole raft of options and settings not available in older digital (or mechanical) controllers.

But the traffic engineers are not setting the timings just so the cops can hassle people. The cops in LFP are just dicks (and always have been).
Posted by Dr_Awesome on July 5, 2013 at 11:05 AM · Report this
Peter Koonz from Portland gave a couple talks in Seattle recently called 'Confessions of a Traffic Engineer':…

He pointed out that a 'traffic failure' means that a vehicle waits at an intersection for more than 80 seconds, but that pedestrians and bicycles are simply not taken into any kind of account.

I agree with Matt above: it's a political decision not to care as much about transit, bikes, and peds.
Posted by ScruffyBallardMan on July 5, 2013 at 11:18 AM · Report this
Fnarf 14
@13, the light cycle at 50th and Stone varies during the day but is never less than 180 seconds (2.5 minutes). For a long time the ped crossing of 50th heading north on the east side of Stone/Green Lake Way would skip one or sometimes two turns, leading to a SEVEN AND A HALF MINUTE WAIT. It's a truly mind-bending experience to see the cars go, and then go again, and then go again. Like something out of Samuel Beckett.
Posted by Fnarf on July 5, 2013 at 11:27 AM · Report this
Yeah, good point, Charles, we should just streets and cities grow undirected and organically. Because that would clearly be better, wouldn't it?

Or maybe, just maybe, as #6 so eloquently put it, you simply change the requirements that the traffic engineers are working to. Because guess what? Engineers don't just do whatever they please, they work to fulfill a specification.
Posted by Jonman on July 5, 2013 at 11:33 AM · Report this
Christ, why is there such a huge anti-intellectual bent to this post? You realize that traffic engineers are strictly limited by political funding decisions, right?

"OH GAWD, TRAFFIC SUCKS" *complains about any new plan to fix traffic or where those locations might be* *votes against new funding sources*
Posted by Solk512 on July 5, 2013 at 11:37 AM · Report this
One more thing, "Dumb device"??

How in the hell is someone supposed to improve something if they have no tools to measure it's current state or the state it's in after changes have been made? That's kindergarten level science there.
Posted by Solk512 on July 5, 2013 at 12:04 PM · Report this
Supreme Ruler Of The Universe 18

Traffic Engineers do what their job title implies...they create Traffic.

If there were no Traffic, then everything would flow freely.

People would take cars to work.

Traffic Engineers must create the traffic that causes the problems that we tax ourselves to fix. And never do.

Salute the Traffic Engineer. Who gives your life purpose!
Posted by Supreme Ruler Of The Universe on July 5, 2013 at 12:04 PM · Report this
Charles Mudede 19
i rest my case with @17. ideology in a state of perfection.
Posted by Charles Mudede on July 5, 2013 at 12:16 PM · Report this
Charles, serious question: are you interested in an actual discussion here or should we just exchange snide remarks?
Posted by Solk512 on July 5, 2013 at 12:21 PM · Report this
Sean Kinney 21
Everything is ideology. And?
Posted by Sean Kinney http:// on July 5, 2013 at 12:47 PM · Report this
Kinison 22
How does Metro know what bus people use before determining which ones to cut? Paper survey mostly, sometimes is card with a serial number for an online survey. Yup, they'll have people wearing smocks handing these out on the bus, because this is the only way they know who takes the bus.
Posted by Kinison on July 5, 2013 at 1:02 PM · Report this
Sandiai 23
All the intersections around here are triggered by cars ONLY. If I'm on my bike and I come up to a red light with no cars going in my direction, I could probably sit there for thirty minutes while cross-traffic stays perpetually green. I don't know what the trigger is, but it's not a camera or infrared sensor, or my presence would trigger it. I suspect it's a plate under the pavement that's triggered by a heavy object. I also notice those counting devices (in the photo) don't count bikes (I don't hear the "click" when I ride over the hose, compared to the audible click made by a car).

Fnarf, you expressed it perfectly:

"It's a truly mind-bending experience to see the cars go, and then go again, and then go again. Like something out of Samuel Beckett."
Posted by Sandiai on July 5, 2013 at 1:06 PM · Report this
Sandiai 24
Long story short: as a bicyclist I either have to break the law or get off my bike and use the pedestrian WALK button to get across many intersections thoughout my day.
Posted by Sandiai on July 5, 2013 at 1:09 PM · Report this
Dr_Awesome 25
Heh. Replace every occurrence of "Traffic Engineer" in Charles' post with "Marxist".

It makes the same sense- none. But it's funnier to read.
Posted by Dr_Awesome on July 5, 2013 at 1:16 PM · Report this
Dr_Awesome 26
@23, 24. By law, an actuated traffic signal must detect all legal vehicles. Including bicycles.

Have you tried calling the City to request a signal technician adjust the loop detectors (they are electric wire loops, not "plates actuated by heavy vehicles")?

Loop detectors are tunable. And often drift out of tune at the expense of detecting smaller vehicles. Or break as the pavement heaves and crumbles over winter.

Also, pneumatic tube counters do count all vehicles, including bicycles. The better counters can break down the vehicle stream by vehicle type, number of axles, speed, direction, and so on. It's really amazing the information one can get from a couple day's worth of tube counts.

Anyway. Not getting service at the signals in your neighborhood? Please call the public works department and request a signal technician look into it.
Posted by Dr_Awesome on July 5, 2013 at 1:21 PM · Report this
Sandiai 27
Thanks, @26!
Posted by Sandiai on July 5, 2013 at 1:40 PM · Report this
Matt from Denver 28
Fnarf, 180 seconds = three minutes.
Posted by Matt from Denver on July 5, 2013 at 2:14 PM · Report this
Fnarf 29
@27, I believe that the small (six-inch) "T" painted in white at the stop line of most intersections is the location of the loop detector. Unless I'm crazy (always a possibility). Position your front wheel over the T and it should detect you.

I know that the left-turn lane at 45th and Stone seems to detect my bike but takes much, much longer to actually give me a signal than my car, but that's anecdotal.
Posted by Fnarf on July 5, 2013 at 2:25 PM · Report this
Fnarf 30
@28, DAG NAB IT. I swear I'm getting senile. Substitute "whole buncha" for "180", please.

Here is proof that the white Ts actually exist:…
Posted by Fnarf on July 5, 2013 at 2:27 PM · Report this
seandr 31
@fnarf: It might be less "mind-bending" if you consider that any car traveling west on 50th will have been waiting in a line stretching several blocks east for at least 3 traffic cycles before it finally gets to cross that intersection.
Posted by seandr on July 5, 2013 at 4:10 PM · Report this
Fnarf 32
@31, no, the cars get to go. I pass through that intersection at least twice a day, sometimes three or four or five times. I know the cycle well. West on 50th gets to go every turn, as does every car lane in sequence. It's slow, because it's five ways, but everyone gets a go.

What's different about the pedestrian crossing is (a) on the west side of the street you have two crosswalks, poorly synced; and (b) on the east side it was once true that the walk signal didn't go when the car light went green. It's fixed now. Now the only thing you have to watch out for is assholes in pickup trucks cutting right through the vet's parking lot at high speed.
Posted by Fnarf on July 5, 2013 at 4:54 PM · Report this
You_Gotta_Be_Kidding_Me 33
Kinda early in the day to be hitting the crack pipe that hard. Don't ya think?
Posted by You_Gotta_Be_Kidding_Me on July 5, 2013 at 4:58 PM · Report this
Sandiai 34
@26 and 29, or I could just wear my cast-iron boots.
(That's some bad joke about metal triggering the circuit). Again, thanks. I had no idea. Apparently, I've been positioning myself at the wrong place in your typical intersection.
Posted by Sandiai on July 5, 2013 at 7:48 PM · Report this
Sandiai 35
@30, no "T's" in Northern Virginian intersections, but I've noticed narrow grooves in the pavement where the wires are no doubt installed.…
Posted by Sandiai on July 5, 2013 at 7:55 PM · Report this
keshmeshi 36
I'd like to know which idiot is responsible for the light cycle under the Ballard Bridge. You have one main street going through and two one-ways on each side. As a pedestrian, trying to cross 15th, I'm given plenty of time to get across one of the one-ways, but the hand stops flashing before I can cross the second. In the meantime, the cross traffic on the second one-way is stopped by a red light for even longer than it would take me to cross. There is no reason why peds can't cross there (and I always do, against the light, because I'm not waiting several minutes to walk 10 feet), except that SDOT hates pedestrians.

And then there's that intersection at NW 54th and 32nd, where drivers pull in to the Locks. There's a fucking *bike and pedestrian* path there, but SDOT, in its infinite wisdom, requires all peds and bikes to press the walk button before you can get a signal to cross legally.
Posted by keshmeshi on July 6, 2013 at 1:01 AM · Report this
Matt from Denver 37
@ 30, they have those in Boulder, and they're marked by a little bicycle painted on the pavement. You roll you're front tire between the painted wheels.
Posted by Matt from Denver on July 6, 2013 at 7:02 AM · Report this
Matt from Denver 38
Er, "your." I really need to learn to patiently proofread before I hit the Post button.
Posted by Matt from Denver on July 6, 2013 at 7:04 AM · Report this
It's purely political. While the science is slowly evolving, it's just as easy to ignore an engineer who gives you a report someone doesn't like as to hire engineers who will be yes men.

Case-in-point: I requested a traffic study at a nearby intersection, pointing out a few obvious changes that were needed. It took a few months, but they finally told me the study was complete and that they had "improved" the intersection. "Improvement" consisted of moving one sign. So, I requested the engineer's report. Through some political wrangling (turns out politicians under threat of prosecution are REALLY responsive to their constituents), I got it, and, well, let's just say that it was completely ignored. The intersection was described by the engineer(s) as "dangerous an inefficient for all road users," "confusing," "unnavigable," and all kinds of other things I could have told you for free. The list of recommended changes was LONG, and, honestly, most of them were cheap-to-free to implement. Re-timing lights & crosswalk signals, installing new signage, re-striping crosswalks, re-striping the lanes to reduce vehicle lanes (they recommended narrowing the road, but indicated that simply reducing vehicle lanes with paint was "feasible"), and clearly marking turn/straight lanes with pavement paint.

Buried in the back was a "letter of interest" from a nearby shopping center indicating that any changes that would slow down vehicle throughput would be "devastating" to their business. Of course this is utter bullshit. People are not going to drive to the next grocery store (several miles away), hardware store (even further), or discount clothing store (downtown with no off-street parking or FAR out into the 'burbs) because it takes them a few more seconds to get through the intersection...particularly if that slight slowdown eliminates or greatly reduces the near-daily accidents at the intersection (which, of course, tie up traffic something wicked and put everyone at risk). To boot, there's ANOTHER entrance to that shopping center away from this intersection, so if someone were really annoyed by sitting at the intersection for a few more seconds, they could easily choose to use the other entrance.

The engineer was correct. The politically-appointed leaders of the the DOT chose to ignore them. Which is pretty ballsy, given that the study was conducted based on a petition I conducted with 500 signatures of local residents. While our elected leaders got a real earful about this at the next meeting (I'm not going to describe DC's confusing local governance system, but suffice it to say a few Councilmembers were there...and, of course, I had shared the results of the study with the neighbors), they clearly don't care. One of these days, someone will be killed there, and that might get them to do something. I'm not holding my breath because I really don't want someone to have to die to get simple, cheap improvements to an intersection.
Posted by Ms. D on July 7, 2013 at 9:23 PM · Report this
FYI cyclists: sometimes the sensor for bikes at lights is a circle in the road as well as the T, or T in a box.

As far as Charle's post goes, I'm sympathetic. If the traffic engineers don't hate cyclists and want them dead they are incredibly incompetent. I'm sure politics thwarts well meaning attempts frequently, but it can't possibly explain everything we have to contend with.

I'll give the traffic engineers one other out. I suspect that the people who paint the sharrows and bike lanes on the road are road raging assholes who want cyclists dead too. It's quite possible it is they are who are often thwarting the will of the engineers.
Posted by K X One on July 7, 2013 at 10:02 PM · Report this
Always ask traffic engineers about the details of their calculations.

For example, the MUTCD has thresholds (traffic volume, number of fatalities) that traffic engineers use to explain why they are not installing a traffic signal at a given location. Question: How where those thresholds developed? Who developed them? My guess is that most traffic engineers have no idea.

Another example, you will hear them say that the 85th percentile speed that drivers are moving at a given location is a "safe speed". What do they mean by "safe"?

Posted by mtma225 on January 25, 2014 at 10:30 PM · Report this

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