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Source: (consider it)
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Thread: Purgatory: Ferguson and its implications
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
Can I also add, that if any of this is actually a law about how to set road limits - as opposed to just a claimed policy with no legal standing - then it provides a golden avenue for someone in the USA to challenge a speeding fine, on the grounds that the speed limit on the road was not lawfully determined.
(And that's exactly why I have these sorts of conversations with MY clients.)
Of course, to try and return from this utter tangent (a fascinating tangent for me, but still a tangent), the black people of Ferguson probably don't have a lot of access to lawyers to make ingenious arguments. They just have to pay the fine.
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Technology has brought us all closer together. Turns out a lot of the people you meet as a result are complete idiots.
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LeRoc
Famous Dutch pirate
# 3216
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Posted
quote:
orfeo: How was the limit on the first one set?
This was a new section of a ring road around a middle-sized city. The limit was first set at 70 km/h, because that's the limit for most ring roads around middle-sized cities in the Netherlands.
I guess this general rule arose historically. Since people started driving cars and since they started building ring roads they did research and tried out several speed limits, and most cities found out that 70 km/h worked best for them.
However in this case, after this section was opened, they found out that a lot of drivers broke the limit, much more than on similar roads around other cities. They also did research that showed to their satisfaction that raising the limit wouldn't give rise to extra accidents etc. So they raised the limit.
quote:
orfeo: You are basically facing the "it's turtles all the way down" problem.
No turtles. The rules-of-thumb 'this is the usual speed limit on a ring road' or 'this is the usal speed limit on a rural road with curves' arose historically.
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I know why God made the rhinoceros, it's because He couldn't see the rhinoceros, so He made the rhinoceros to be able to see it. (Clarice Lispector)
Posts: 9474 | From: Brazil / Africa | Registered: Aug 2002
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Dave W.
Shipmate
# 8765
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Posted
quote:
Originally posted by orfeo:
Can I also add, that if any of this is actually a law about how to set road limits - as opposed to just a claimed policy with no legal standing - then it provides a golden avenue for someone in the USA to challenge a speeding fine, on the grounds that the speed limit on the road was not lawfully determined.
Two days ago you had no idea how US transportation authorities set speed limits. Since then, you've written north of 1500 words on the topic, concluding that they're all lying about how they do it, and now you think you may actually have found a fool-proof defense against speeding tickets.
Allow me to say that I am highly skeptical when you say "this is exactly what I spend my days doing", if by "this" you mean anything like writing manuals for guiding traffic engineers in doing their job.
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lilBuddha
Shipmate
# 14333
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Posted
Engineering software for roads, including the American versions, will give you a guideline for safe speed. It reference lines of sight, the angle of the roadway through curves, intersecting roadways, anticipated traffic load, etc.
Pity none of the research, maths and experience goes into the decisions for speed limits.
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I put on my rockin' shoes in the morning
Hallellou, hallellou
Posts: 17627 | From: the round earth's imagined corners | Registered: Dec 2008
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
quote:
Originally posted by Dave W.:
quote:
Originally posted by orfeo:
Can I also add, that if any of this is actually a law about how to set road limits - as opposed to just a claimed policy with no legal standing - then it provides a golden avenue for someone in the USA to challenge a speeding fine, on the grounds that the speed limit on the road was not lawfully determined.
Two days ago you had no idea how US transportation authorities set speed limits. Since then, you've written north of 1500 words on the topic, concluding that they're all lying about how they do it, and now you think you may actually have found a fool-proof defense against speeding tickets.
Allow me to say that I am highly skeptical when you say "this is exactly what I spend my days doing", if by "this" you mean anything like writing manuals for guiding traffic engineers in doing their job.
I doubt that it's lying, in terms of being consciously aware of the logical knot and doing it anyway.
I've written rules to guide offshore petroleum exploration, auctions, telephone numbering, OH&S licensing, patent applications, awarding export quotas, imports of chemicals, fishing licences, prescribing anti-cancer drugs, setting the prices of drugs, labelling wine, labelling appliances for water efficiency, and calculating superannuation.
To name a few highlights.
Do you know what one of the most common forms of comment is from my clients? "Wow. You've sure learnt a lot about this subject in the couple of days since you started the job."
You can be sceptical all you like, but I've walked into a meeting of geologists and discussed with them at length whether they are accurately describing the data that's required in an oil exploration report, and had them agree that I'm right and that their previous guidelines were imprecise. I know what I do, and I know I'm good at it.
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
And in fact I can think of at least one job where I've had to have the same kind of conversation about the timing problem - that you can't use a fact as a decision-making criterion if the fact won't exist at the time the decision must be made.
It had to do with providing telephone and internet services to new housing developments. You appear to believe that, because I have no real expertise in telecommunications technology, the construction industry or real estate sales, I had no capacity to point out that you can't know certain things about a building or group of buildings when they haven't been built yet.
[ 19. March 2015, 01:30: Message edited by: orfeo ]
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Technology has brought us all closer together. Turns out a lot of the people you meet as a result are complete idiots.
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Dave W.
Shipmate
# 8765
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Posted
I'm sure Australia must be very lucky indeed to have such a wonderfully talented person.
And yet, for all your self-proclaimed expertise, you can't seem to figure out how or why traffic engineers can integrate surveys of observed speeds into a procedure for zoning speed limits. It's rather reminiscent of the apocryphal story of the scientist who proved that bumblebees can't fly.
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
quote:
Originally posted by Dave W.:
I'm sure Australia must be very lucky indeed to have such a wonderfully talented person.
And yet, for all your self-proclaimed expertise, you can't seem to figure out how or why traffic engineers can integrate surveys of observed speeds into a procedure for zoning speed limits. It's rather reminiscent of the apocryphal story of the scientist who proved that bumblebees can't fly.
I understand perfectly how they can do it once there is traffic. I'd be deeply fascinated about your insights as to how they can integrate such a survey into the procedure for establishing the speed limit on a road that no-one has driven on yet.
While you're at it, can you please calculate my tax income returns for the next 5 years? I don't know what my income will be yet, but apparently that's no bother.
*Mutters to self* Relational definitions. It's all in relational definitions...
[ 19. March 2015, 02:30: Message edited by: orfeo ]
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Dave W.
Shipmate
# 8765
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Posted
quote:
Originally posted by orfeo:
quote:
Originally posted by Dave W.:
I'm sure Australia must be very lucky indeed to have such a wonderfully talented person.
And yet, for all your self-proclaimed expertise, you can't seem to figure out how or why traffic engineers can integrate surveys of observed speeds into a procedure for zoning speed limits. It's rather reminiscent of the apocryphal story of the scientist who proved that bumblebees can't fly.
I understand perfectly how they can do it once there is traffic. I'd be deeply fascinated about your insights as to how they can integrate such a survey into the procedure for establishing the speed limit on a road that no-one has driven on yet.
Same answer as before. Set a provisional limit based on similar roads (or the design speed), then do the survey, then set the permanent limit. Are you unfamiliar with the concept of an iterative process?
Posts: 2059 | From: the hub of the solar system | Registered: Nov 2004
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
I'm not unfamiliar with iterative processes. I'm trying to point out, patiently, that the transport authorities in the USA don't appear to be talking about the starting point, they're only talking about the review process afterwards.
The fact that you can come up with a process of setting a provisional speed limit merely highlights that the links you provide DON'T TALK ABOUT THIS PROCESS! Which is actually the most important part for any road that is never reviewed.
It's backwards. Compare that to the Australian material which clearly sets out the factors for setting your first speed limit, and then also discusses how to review it.
[ 19. March 2015, 04:18: Message edited by: orfeo ]
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Technology has brought us all closer together. Turns out a lot of the people you meet as a result are complete idiots.
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LeRoc
Famous Dutch pirate
# 3216
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Posted
quote:
orfeo: I'm not unfamiliar with iterative processes. I'm trying to point out, patiently, that the transport authorities in the USA don't appear to be talking about the starting point, they're only talking about the review process afterwards.
Maybe they don't talk about it because it's trivial. Most people on this thread seem to think that, and they have already pointed out the most likely procedure for getting a starting point. It's just common sense. I really can't see why this talk about a starting point is so important to you.
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I know why God made the rhinoceros, it's because He couldn't see the rhinoceros, so He made the rhinoceros to be able to see it. (Clarice Lispector)
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Dave W.
Shipmate
# 8765
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Posted
quote:
Originally posted by orfeo:
The fact that you can come up with a process of setting a provisional speed limit merely highlights that the links you provide DON'T TALK ABOUT THIS PROCESS! Which is actually the most important part for any road that is never reviewed.
Surely you don't expect me to find all the details for you, of all people? It would be insufferably rude and/or foolish for me to try to show you up in such a manner.
Since you describe yourself as an expert on these sorts of things, however, perhaps you wouldn't mind answering this: Suppose an expert in (whatever it is that you do) were to begin working with a client like an American state transportation agency, and as part of the work the expert needed to understand the existing method of setting speed limits. If the client started to describe the current practice, and said something that the expert (not being an expert on this particular topic) didn't understand on first hearing, would it be normal for the expert to immediately tell the client that they were lying?
Posts: 2059 | From: the hub of the solar system | Registered: Nov 2004
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
No, when doing this for money I usually find more polite ways of conveying to someone that they haven't thought things through properly.
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Technology has brought us all closer together. Turns out a lot of the people you meet as a result are complete idiots.
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
quote:
Originally posted by LeRoc:
Maybe they don't talk about it because it's trivial. Most people on this thread seem to think that, and they have already pointed out the most likely procedure for getting a starting point. It's just common sense. I really can't see why this talk about a starting point is so important to you.
Common sense? That's the thing about legal disputes, you suddenly discover that people's "common sense" wasn't actually common.
You and DaveW both agree that you go and find "similar" roads to set the initial speed limit. I'd bet a large sum, though, that if I asked each of you to go and write down what would make 2 roads "similar", you wouldn't come up with the same answer. You'd probably have some things in common, yes, but they wouldn't be the same.
One of you, for example, might focus entirely on the driving experience and talk about the width of the road, the number of lanes, how curvy it was, and whether the surface was smooth.
The other one of you might, because you're thinking of your local neighbourhood that you also use as a pedestrian, talk about how built-up the area surrounding the road is, the amount of foot traffic, whether there are driveways that cars are coming in and out of, and so on.
Neither of these lists would be wrong, but they would be different. And for any given road they could lead to very different decisions.
Fundamentally, it's perfectly possible for people around a table to all nod their heads in agreement with the principle (yes, you pick "similar" roads), and then all leave the meeting satisfied, not realising that they have absolutely no agreement as to what that's actually going to mean. And when one of those people goes and sets a speed limit based on a "similar" road, the others will end up saying "Why the hell did you pick that for comparison? It's not similar at all!"
As to whether it's trivial, people seem to spend a great deal of time talking about speed limits - not least when they're being fined for speeding and start talking about "speed traps", which is exactly how this tangent started. If you think the speed limit should be higher, and you've got what you think are rational, objective reasons for why it should be higher, is it trivial that the authorities haven't set it where you think it should be? Wouldn't you want to know why they set it at the speed that they did?
[ 19. March 2015, 11:02: Message edited by: orfeo ]
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Technology has brought us all closer together. Turns out a lot of the people you meet as a result are complete idiots.
Posts: 18173 | From: Under | Registered: Jul 2008
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
quote:
Originally posted by Dave W.:
Suppose an expert in (whatever it is that you do) were to begin working with a client like an American state transportation agency, and as part of the work the expert needed to understand the existing method of setting speed limits. If the client started to describe the current practice, and said something that the expert (not being an expert on this particular topic)
Dammit. I'm going to say this because it's been bugging me for hours.
What exactly do you think I need to be an expert in here?
What is difficult to understand about "speed limit" or "85th percentile"? Why are you talking about these things, if it requires expertise? Why is there a cheery little video from Maine explaining it in 10 minutes if it's difficult?
What is difficult about the concept that you can't measure traffic until there's traffic?
None of this requires any expertise in traffic flow. I don't need to understand how they worked out that the 85th percentile was safest, rather than the 50th percentile or the 70th percentile. I haven't challenged that, once. I'm not remotely interested in challenging it. I'm not interested in challenging whatever data the transport authorities in Austrlia have that led them to set a criteria that talks about the width of a verge being at least 5.6 metres. I wouldn't know the first thing about how they arrived at the figure. It's just a figure.
You seem, in the midst of your desire to throw in snarky little personal attacks because how dare I suggest I know a hell of a lot about the logical structuring of decision-making criteria, what with a job that less than 150 people in this country do (and perhaps even fewer in the USA, which has no tradition of professional legislative drafting) and what with having had to reapply for my own job against my peers and achieving the top rank with a score half a point off perfect, to be under a severe misapprehension as to exactly what I'm claiming to know.
It doesn't take expertise in transportation infrastructure to understand that you can't measure something before it exists. That's got nothing to DO with transportation infrastructure. I can't measure my income tax until I have an income. I can't measure the amount of rainfall before it's rained. I can't measure the final number of posts in this thread until the thread has been locked. I can't tell you how many years Barack Obama lived because he isn't dead yet.
I'm not going to apologise to you for being able to spot that logical problem in about 30 seconds, or be falsely modest about it, because that's fundamental to what I'm paid to do every day, and when I mentioned this stuff to a colleague today it took them about 30 seconds as well. The whole reason my job is specialist is because most people can't see that so quickly, and in any case like any skill it's honed through practice.
The 85th percentile of an empty data set doesn't exist. What the empty data set is about is completely irrelevant to that proposition.
[ 19. March 2015, 13:21: Message edited by: orfeo ]
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Technology has brought us all closer together. Turns out a lot of the people you meet as a result are complete idiots.
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Beeswax Altar
Shipmate
# 11644
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Posted
quote:
originally posted by orfeo:
The whole reason my job is specialist is because most people can't see that so quickly, and in any case like any skill it's honed through practice.
I hate to burst your bubble but I saw it rather quickly myself. ![[Big Grin]](biggrin.gif)
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Losing sleep is something you want to avoid, if possible.
-Og: King of Bashan
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
You could have said!
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Technology has brought us all closer together. Turns out a lot of the people you meet as a result are complete idiots.
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LeRoc
Famous Dutch pirate
# 3216
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Posted
quote:
orfeo: You and DaveW both agree that you go and find "similar" roads to set the initial speed limit. I'd bet a large sum, though, that if I asked each of you to go and write down what would make 2 roads "similar", you wouldn't come up with the same answer. You'd probably have some things in common, yes, but they wouldn't be the same.
It doesn't matter. It's just a provisional speed limit. The only imortant thing here is to try not to have any grave accidents while the provisional speed limit is in force.
Even if two road planners look eachother in the eyes and say to eachother "What do you think, is 60 km/h ok?" "Let's put it at 50 to be on the safe side." That's fine with me.
The only legal aspect here is that the signposted speed should be followed by the drivers.
I really don't see what the problem is here.
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I know why God made the rhinoceros, it's because He couldn't see the rhinoceros, so He made the rhinoceros to be able to see it. (Clarice Lispector)
Posts: 9474 | From: Brazil / Africa | Registered: Aug 2002
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Dave W.
Shipmate
# 8765
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Posted
Gwai:
Aye, aye!
LeRoc:
While the method you describe has the virtue of charming informality, I don't think I'd go that far. I'm sticking (provisionally) with the idea of provisional limits as a way out of orpheo's conundrum, but I do think they'd need to be a little more formal than that.
Orpheo:
quote:
What exactly do you think I need to be an expert in here?
Sorry, let me attempt to be clearer. I mean you are not expert in the sense that you do not possess a close familiarity with the existing regulations and practices involved in setting speed limits in the US.
There's no particular reason why you should - I don't either, and we're probably both better off for it. But I would argue that since we aren't familiar with the details, it is entirely reasonable to assume that, when one provision of the regulations appears to entail a logical impossibility, there may well be another provision of the regulations which entirely resolves it.
In this case, the claim is that measurements of existing traffic flow are used in setting speed limits (but not to the exclusion of all other considerations.) This is consistent with the legal requirements of the California Vehicle Code (links available on request.)
You object that newly constructed roads have no traffic to be measured. True - but if Caltrans has some plausible, consistent basis for setting limits in advance of the engineering and traffic survey, doesn't this resolve the logical conundrum? We (not being experts in the sense outlined above) may not happen to know what this basis is, but as long as there could be one, it seems reasonable to me to assume that in fact there is, and we just don't know it.
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
In response to both of the last 2 posts:
Whether it's a problem depends on whether you're fine with a law that says "we decide the speed limits, and we don't have to explain to you how we set them, and it's basically up to us to choose our method".
In my experience most people aren't fine with laws like that, but maybe I experience a biased sample.
However, I'd argue that where we started on this tangent - with complaints about speed traps - tends to show that people don't just go "oh well, the only legal issue here is that I have to comply with the speed limit no matter how irrational or arbitrary or mysterious I think the speed limit is".
People demonstrate that they DO what to know how speed limits are set, by complaining when they can't see the reason why a particular speed limit was set. They start attributing reasons - first and foremost, the reason they attribute is "raising revenue".
[ 20. March 2015, 01:49: Message edited by: orfeo ]
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Dave W.
Shipmate
# 8765
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Posted
Actually I was asking if it would resolve your logical conundrum, not whether it was a problem in the sense of someone not "being fine with the law". (I'll assume the answer to the former is now yes.)
As for "we don't have to explain to you how we set them" - I don't concede that this is the situation. I'm actually pretty happy with the detail that I've been able to find about the process for setting and adjusting speed limits on existing roads, and I see no reason to consider it mysterious - the 91-page California Manual for Setting Speed Limits is sufficient. (Again, links available on request.)
That I don't know the details of how limits are set on brand new construction doesn't particularly bother me. I can envision several reasonable alternatives, so I consider it neither an insuperable logical barrier; and I don't think my unfamiliarity with traffic engineering regulations is necessarily an indication that the law is irrational, arbitrary, or mysterious.
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Palimpsest
Shipmate
# 16772
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Posted
In Washington State, there's a Speed Limit Law that among other things has the default speed limits for different types of road. If a road is not posted with speed limits, it has the default limits.
So that allows the unmeasured road if it's needed. In practice it's probably set by experience. I haven't heard of any successful challenging of speed limits, despite things like the statewide highway speed limit drop due to federal regulations.
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RuthW
liberal "peace first" hankie squeezer
# 13
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Posted
quote:
Originally posted by orfeo:
You and DaveW both agree that you go and find "similar" roads to set the initial speed limit. I'd bet a large sum, though, that if I asked each of you to go and write down what would make 2 roads "similar", you wouldn't come up with the same answer. You'd probably have some things in common, yes, but they wouldn't be the same.
One of you, for example, might focus entirely on the driving experience and talk about the width of the road, the number of lanes, how curvy it was, and whether the surface was smooth.
The other one of you might, because you're thinking of your local neighbourhood that you also use as a pedestrian, talk about how built-up the area surrounding the road is, the amount of foot traffic, whether there are driveways that cars are coming in and out of, and so on.
I find the notion that anyone would build a road and only afterward consider what the speed limit should be pretty ludicrous.
When roads are built in California, they are built to certain engineering standards. They don't just pour concrete and lay asphalt and then look at it and try to figure out what might be safe. CalTrans or the local city or county or whoever knows what the speed limit is going to be on a road before it's even built.
Building freeways takes a lot of engineering. Freeway engineers know what the road surface materials are going to be, how steeply pitched the curves are going to be, etc. And they know that the maximum speed limit on a divided highway in California is 65 mph, so they make decisions about things like curves in freeways with that in mind.
The California Vehicle Code fixes other speed limits, too. For instance, by state law roads in residential and business districts less than 40 feet wide have a 25 mph speed limit, and it takes an engineering and traffic study for a municipality to change that. A few years ago the state legislature tightened up the rules on that, so a city has to have a study showing that there is something about the road not apparent to an ordinary driver that makes a lower limit necessary if they want to lower the speed limit. Municipalities aren't allowed to just lower the limit because they want to and then ticket people.
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
1. Whether it would resolve the logical conundrum depends on what it is. If it's based on actual qualities of the road and surrounds, then yes. You'd have to wonder, though, why on earth you would then abandon the actual qualities of the road and surrounds and base your later reviews entirely on "how fast drivers have decided to go".
2. The Washington State law does not give primacy to the 85th percentile rule.
3. Neither, I would argue, does the Californian law, although the manual does continue the mysterious implicit assumption that 15% of all drivers will drive at an unsafe speed (which is not logically equivalent to the finding that the 85th percentile is the speed at which your chances of being in a collision are lowest).
4. Ruth's comments are entirely logical.
[ 20. March 2015, 05:24: Message edited by: orfeo ]
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RuthW
liberal "peace first" hankie squeezer
# 13
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Posted
The 85 percentile thing works because in general cops around here give speeding tickets for unsafe speeding. The speed limit on the freeway is 65, but when conditions permit people drive 70 and no one gets a ticket for that. The person who gets a ticket for speeding is the person who is going faster than the flow of traffic -- because that's what's not safe.
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lilBuddha
Shipmate
# 14333
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Posted
quote:
Originally posted by orfeo:
4. Ruth's comments are entirely logical.
Perhaps a little wordy, but yeah.
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I put on my rockin' shoes in the morning
Hallellou, hallellou
Posts: 17627 | From: the round earth's imagined corners | Registered: Dec 2008
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Palimpsest
Shipmate
# 16772
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Posted
quote:
Originally posted by orfeo:
2. The Washington State law does not give primacy to the 85th percentile rule.
The chapter I cited references
RCW 46.61.405 which says
quote:
Whenever the secretary of transportation shall determine upon the basis of an engineering and traffic investigation that any maximum speed herein before set forth is greater than is reasonable or safe with respect to a state highway under the conditions found to exist at any intersection ...
The 85% rule would come under the that description if that was considered standard engineering practice in the other links various others have put in this thread.
I guess the United States will just have to continue to get along without your special talents.
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
quote:
Originally posted by RuthW:
The 85 percentile thing works because in general cops around here give speeding tickets for unsafe speeding. The speed limit on the freeway is 65, but when conditions permit people drive 70 and no one gets a ticket for that. The person who gets a ticket for speeding is the person who is going faster than the flow of traffic -- because that's what's not safe.
Well, "faster than the flow of traffic" does work as a principle for cops in deciding who to book.
Not entirely sure that corresponds to the 85th percentile thing, though. It might in practice: the median speed is the 50th percentile but the distribution is likely to be highly compressed so that in fact everyone from 15th to 85th percentile might be doing a really similar speed. But I can guarantee you that 84.9% of the traffic is moving at a slower speed, however fractionally.
The obvious reason for "faster than the flow of traffic", though, is that the cops don't have the resources to book everybody and a faster car (1) will stand out, and (2) is arguably more morally deserving of a ticket.
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Technology has brought us all closer together. Turns out a lot of the people you meet as a result are complete idiots.
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
quote:
Originally posted by Palimpsest:
I guess the United States will just have to continue to get along without your special talents.
...such as understanding what the word "primacy" means?
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Technology has brought us all closer together. Turns out a lot of the people you meet as a result are complete idiots.
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RuthW
liberal "peace first" hankie squeezer
# 13
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Posted
Sorry, lilBuddha -- I should have noted that you'd already made this point.
quote:
Originally posted by orfeo:
You'd have to wonder, though, why on earth you would then abandon the actual qualities of the road and surrounds and base your later reviews entirely on "how fast drivers have decided to go".
Engineering and traffic studies take into account both the actual qualities of the road and surrounds and how fast drivers have decided to go, as well as looking at whether or not the speed drivers have chosen has led to lots of accidents. If people are going too fast for a particular stretch of road, they'll put in traffic calming measures rather than simply lower speed limits, because lowering speed limits simply doesn't work -- most people drive more by what makes sense to them than by the posted speed limit, and lowering speed limits doesn't actually make people drive more slowly. If it did, cities that set speed traps wouldn't make any money from them.
The speed that most drivers choose works because traffic is safest when everyone is going about the same speed and because most people don't want to crash their cars and drive accordingly.
Posts: 24453 | From: La La Land | Registered: Apr 2001
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RuthW
liberal "peace first" hankie squeezer
# 13
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Posted
quote:
Originally posted by orfeo:
The obvious reason for "faster than the flow of traffic", though, is that the cops don't have the resources to book everybody and a faster car (1) will stand out, and (2) is arguably more morally deserving of a ticket.
Morality has nothing to do with it. The reason is because not going with the flow of traffic is what's most dangerous about speeding. It's why you can also get a ticket for driving too slowly on the freeway.
[ 20. March 2015, 06:00: Message edited by: RuthW ]
Posts: 24453 | From: La La Land | Registered: Apr 2001
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lilBuddha
Shipmate
# 14333
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Posted
quote:
Originally posted by RuthW:
Sorry, lilBuddha -- I should have noted that you'd already made this point.
No worries, the snark was not aimed at you.
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I put on my rockin' shoes in the morning
Hallellou, hallellou
Posts: 17627 | From: the round earth's imagined corners | Registered: Dec 2008
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Palimpsest
Shipmate
# 16772
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Posted
Ruth has this right. The latest theory in Traffic engineering is remove traffic signs to make streets safe. The theory is that removing signs in city and town streets makes people pay more attention to others and makes it safer because the signs make people think it's a divided highway. They still ticket people for going much faster than the flow of traffic.
This a Dutch and Scandinavian approach, but they're trying it here in Seattle with limited success because the streets are being overwhelmed with more traffic.
None of this has much to do with the problems of Ferguson of course.
[ 20. March 2015, 06:07: Message edited by: Palimpsest ]
Posts: 2990 | From: Seattle WA. US | Registered: Nov 2011
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RuthW
liberal "peace first" hankie squeezer
# 13
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Posted
The relevance to Ferguson comes in with the discretion allowed to police officers when stopping people for traffic violations. In a society that still has systemic racism, if you're black or brown and you get stopped and ticketed by a white cop for going 70 on the freeway when everyone else was also going 70, you're going to have to wonder if your skin color was a factor.
Posts: 24453 | From: La La Land | Registered: Apr 2001
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
quote:
Originally posted by RuthW:
quote:
Originally posted by orfeo:
The obvious reason for "faster than the flow of traffic", though, is that the cops don't have the resources to book everybody and a faster car (1) will stand out, and (2) is arguably more morally deserving of a ticket.
Morality has nothing to do with it. The reason is because not going with the flow of traffic is what's most dangerous about speeding. It's why you can also get a ticket for driving too slowly on the freeway.
I said "morally" because legally everyone who speeds is liable for a ticket.
Which also is relevant to your point (and I think I may have made a similar point somewhere in this unholy mess): that picking which person, out of all the speeding people, to give a ticket to based on race is not what we want to happen.
Posts: 18173 | From: Under | Registered: Jul 2008
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Dave W.
Shipmate
# 8765
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Posted
quote:
Originally posted by orfeo:
1. Whether it would resolve the logical conundrum depends on what it is. If it's based on actual qualities of the road and surrounds, then yes.
A logical conundrum that is so easily sidestepped is not much of a conundrum, is it? quote:
You'd have to wonder, though, why on earth you would then abandon the actual qualities of the road and surrounds and base your later reviews entirely on "how fast drivers have decided to go".
I agree that would be odd - but it's also nothing like what I've described. quote:
2. The Washington State law does not give primacy to the 85th percentile rule.
I hope you don't think primacy means "base your later reviews entirely on" - and as Palimpsest notes, other provisions point to the use of traffic studies, which will likely lead to a manual emphasizing the 85th percentile measure. quote:
3. Neither, I would argue, does the Californian law, ...
The California law requires Caltrans use engineering and traffic surveys, which must consider prevailing speeds - listed as first required element, in fact. quote:
... although the manual does continue the mysterious implicit assumption that 15% of all drivers will drive at an unsafe speed (which is not logically equivalent to the finding that the 85th percentile is the speed at which your chances of being in a collision are lowest)..
...
Now you seem to be including a mysterious assumption that the posted speed limit is supposed to indicate a sharp distinction between safe and unsafe speeds - this is nowhere supported by the contents of the manual. quote:
4. Ruth's comments are entirely logical.
Glad we can agree on something!
Posts: 2059 | From: the hub of the solar system | Registered: Nov 2004
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
quote:
Originally posted by Dave W.:
quote:
Originally posted by orfeo:
1. Whether it would resolve the logical conundrum depends on what it is. If it's based on actual qualities of the road and surrounds, then yes.
A logical conundrum that is so easily sidestepped is not much of a conundrum, is it?
It seems to me you have been completely misunderstanding the nature of my observations. The "conundrum" is simply the disparity between the claimed method of speed limit setting and the rules of logic. I've been pointing out solutions to the "conundrum" the entire time, and the entire point of what I've been saying all along is that the claimed method of speed limit setting cannot be the actual method. I never suggested it was actually difficult to set speed limits.
But "well, you know what I actually meant" is one thing you simply cannot get away with in the business of writing laws. Near enough is not good enough. That's the viewpoint I'm coming from. In my office, writing something that cannot literally be followed is exactly what we're trying to avoid.
quote:
Now you seem to be including a mysterious assumption that the posted speed limit is supposed to indicate a sharp distinction between safe and unsafe speeds - this is nowhere supported by the contents of the manual.
Perahaps, but it's a sharp distinction between lawful and unlawful speeds. I'm not sure which option you're taking - that they are making some safe speeds unlawful, or that they are allowing some unsafe speeds to be lawful. It is, however one of the fundamental oddities of the claimed system that the safest possible speed is also the lawful maximum, meaning that you are only allowed to fall on one side of the 'middle' speed in safety terms.
[ 20. March 2015, 12:00: Message edited by: orfeo ]
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Technology has brought us all closer together. Turns out a lot of the people you meet as a result are complete idiots.
Posts: 18173 | From: Under | Registered: Jul 2008
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Dave W.
Shipmate
# 8765
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Posted
quote:
Originally posted by orfeo:
quote:
Originally posted by Dave W.:
quote:
Originally posted by orfeo:
1. Whether it would resolve the logical conundrum depends on what it is. If it's based on actual qualities of the road and surrounds, then yes.
A logical conundrum that is so easily sidestepped is not much of a conundrum, is it?
It seems to me you have been completely misunderstanding the nature of my observations. The "conundrum" is simply the disparity between the claimed method of speed limit setting and the rules of logic. I've been pointing out solutions to the "conundrum" the entire time, and the entire point of what I've been saying all along is that the claimed method of speed limit setting cannot be the actual method. I never suggested it was actually difficult to set speed limits.
It seems to me I understand the nature of your observations, it's just that I think you're observing a straw man. It's only a problem if the entirety of the "claimed method" is "we only ever use the 85th percentile", but I don't think that's a claim anyone is actually making. quote:
quote:
Now you seem to be including a mysterious assumption that the posted speed limit is supposed to indicate a sharp distinction between safe and unsafe speeds - this is nowhere supported by the contents of the manual.
Perahaps, but it's a sharp distinction between lawful and unlawful speeds. I'm not sure which option you're taking - that they are making some safe speeds unlawful, or that they are allowing some unsafe speeds to be lawful.
If there isn't actually a sharp distinction between safe and unsafe speeds, then posted speed limits will always fall into one of these two categories, regardless of how they they're established. quote:
It is, however one of the fundamental oddities of the claimed system that the safest possible speed is also the lawful maximum, meaning that you are only allowed to fall on one side of the 'middle' speed in safety terms.
This is another thing you've imported into the "claimed method" which doesn't seem to actually show up in (e.g.) the California speed limit manual previously cited, which says: quote:
Speed limits that are set near the 85th percentile speed of free flowing traffic are safer and produce less variance in vehicle speeds.
Posts: 2059 | From: the hub of the solar system | Registered: Nov 2004
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LeRoc
Famous Dutch pirate
# 3216
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Posted
Let's look at this mathematically. Define the function f(x) as follows:
code:
f(x) = the maximum speed at which the 85% slowest percentile cars drive when the speed limit is set at x
For example, if the speed limit is set at 40 mph, then the 85% percent of the cars drive below 50 mph. So, f(40)=50.
The thing is, we don't know f(x). We don't have a function description for it. We have just built the road, we haven't measured anything yet.
What we are looking for is a value of X for which f(X)=X. In other words, a speed limit at which 85% of the cars drive slower than the limit.
The easiest way to do this, is to pick an initial speed x_0. Any x_0. Any initial guess for the speed will do, but of course the better we can guess it to be closer to X (which we don't know), the faster we'll find X. So we make an educated guess, based on similar roads. We don't need an exact definiton of what 'similar' is, but the more similar the other roads we choose will be, the faster we'll find X.
What we do then, is we define:
x_1=f(x_0)
X_2=f(x_1)
x_3=f(X_2)
etc.
If the function f satisfies certain mathematical conditions (which normally it will), this series will converge rather rapidly to X. And there we have our answer!
Of course, in practice it doesn't work as smoothly as this. We can't just change the speed limit every day. And of course we must make sure that no accidents happen (we can't set the speed limit ridiculously high).
But there is no logical contradiction here.
This is rather normal in iterative methods for numerical problem solving. You have to specify an initial guess x_0. Any guess will do, but the better you guess, the faster your method will converge.
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I know why God made the rhinoceros, it's because He couldn't see the rhinoceros, so He made the rhinoceros to be able to see it. (Clarice Lispector)
Posts: 9474 | From: Brazil / Africa | Registered: Aug 2002
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romanlion
editorial comment
# 10325
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Posted
quote:
Originally posted by orfeo:
But "well, you know what I actually meant" is one thing you simply cannot get away with in the business of writing laws.
Don't tell that to ACA advocate Donald Verrilli.
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"You can't get rich in politics unless you're a crook" - Harry S. Truman
Posts: 1486 | From: White Rose City | Registered: Sep 2005
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Barnabas62
Shipmate
# 9110
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Posted
Is that a reference to some quote by Donald Verrilli? If so, which one? Cryptic references hardly help discussions. I know a little about Verrilli's 2012 Supreme Court appearance, following which he took a bit of a hammering from (amongst others) that well known conservative Jon Stewart. Maybe you're referring back to that "old news"?
I can see a kind of relevance to the tangent, but the discussion seems to be moving further and further away from the main thread purpose.
Barnabas62
Purgatory Host
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Who is it that you seek? How then shall we live? How shall we sing the Lord's song in a strange land?
Posts: 21397 | From: Norfolk UK | Registered: Feb 2005
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romanlion
editorial comment
# 10325
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Posted
quote:
Originally posted by Barnabas62:
I know a little about Verrilli's 2012 Supreme Court appearance.....Maybe you're referring back to that "old news"?
Barnabas62
Purgatory Host
I was referring to his 2015 appearance. Two week "old news".
Alito tends to agree with orfeo. From the article:
Probably the toughest questions for Verrilli came from Justice Samuel Alito, who repeatedly pressed him about why the Supreme Court shouldn’t read the disputed language to mean subsidies can only go to people living in certain states. “If Congress did not want the phrase ‘established by the state’ to mean what that would normally be taken to mean, why did they use that language?” he asked Verrilli.
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"You can't get rich in politics unless you're a crook" - Harry S. Truman
Posts: 1486 | From: White Rose City | Registered: Sep 2005
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Barnabas62
Shipmate
# 9110
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Posted
Thanks, that makes more sense. It would help me (and I suspect others who live outside the US) if you could provide links to clarify similar topical references in future. The current affairs news agenda in the US doesn't always cross the various ponds.
[I appreciate Google is our friend].
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Who is it that you seek? How then shall we live? How shall we sing the Lord's song in a strange land?
Posts: 21397 | From: Norfolk UK | Registered: Feb 2005
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orfeo
Ship's Musical Counterpoint
# 13878
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Posted
quote:
Originally posted by romanlion:
quote:
Originally posted by Barnabas62:
I know a little about Verrilli's 2012 Supreme Court appearance.....Maybe you're referring back to that "old news"?
Barnabas62
Purgatory Host
I was referring to his 2015 appearance. Two week "old news".
Alito tends to agree with orfeo. From the article:
Probably the toughest questions for Verrilli came from Justice Samuel Alito, who repeatedly pressed him about why the Supreme Court shouldn’t read the disputed language to mean subsidies can only go to people living in certain states. “If Congress did not want the phrase ‘established by the state’ to mean what that would normally be taken to mean, why did they use that language?” he asked Verrilli.
That was very interesting reading.
Most interesting to me was Justice Scalia, who was not impressed by any attempt to try to make the statute as a whole make sense. He wouldn't like our High Court much, where looking at the overall context is generally considered quite important.
But yeah, judges here will generally say "those words must be there for a reason/must have some work to do". In fact, in one or two very recent cases drafters got a mention, which always makes it interesting... professional drafters don't really exist in the same way in the USA, so they're only likely to talk about "Congress".
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Technology has brought us all closer together. Turns out a lot of the people you meet as a result are complete idiots.
Posts: 18173 | From: Under | Registered: Jul 2008
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Dave W.
Shipmate
# 8765
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Posted
quote:
Originally posted by romanlion:
quote:
Originally posted by Barnabas62:
I know a little about Verrilli's 2012 Supreme Court appearance.....Maybe you're referring back to that "old news"?
Barnabas62
Purgatory Host
I was referring to his 2015 appearance. Two week "old news".
Alito tends to agree with orfeo. From the article:
Probably the toughest questions for Verrilli came from Justice Samuel Alito, who repeatedly pressed him about why the Supreme Court shouldn’t read the disputed language to mean subsidies can only go to people living in certain states. “If Congress did not want the phrase ‘established by the state’ to mean what that would normally be taken to mean, why did they use that language?” he asked Verrilli.
In the 2012 case, plaintiff's advocate Carvin (same one arguing in 2015) and the dissenting conservative justices all agreed that would obviously collapse without federal subsidies. Unless one thinks that Congress intended to set up exchanges that would obviously collapse, that would seem to be a pretty good reason "why the Supreme Court shouldn’t read the disputed language to mean subsidies can only go to people living in certain states."
Posts: 2059 | From: the hub of the solar system | Registered: Nov 2004
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romanlion
editorial comment
# 10325
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Posted
quote:
Originally posted by Dave W.:
Unless one thinks that Congress intended to set up exchanges that would obviously collapse....
Congress intended the states to set up exchanges as a requirement to qualify for subsidization. This is clear.
They applied a cudgel to recalcitrant states which may now come back and crack their skulls instead.
See here.
And here.
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"You can't get rich in politics unless you're a crook" - Harry S. Truman
Posts: 1486 | From: White Rose City | Registered: Sep 2005
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Barnabas62
Shipmate
# 9110
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Posted
Separate thread, guys? It looks like it might have a bit of mileage, but it sure ain't an implication of Ferguson.
I'm going to suspend this thread for an hour while I set up a new one.
B62, Purg Host
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Who is it that you seek? How then shall we live? How shall we sing the Lord's song in a strange land?
Posts: 21397 | From: Norfolk UK | Registered: Feb 2005
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Barnabas62
Shipmate
# 9110
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Posted
New thread here. Please move any continuation of this tangent to that thread.
B62, Purg Host
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Who is it that you seek? How then shall we live? How shall we sing the Lord's song in a strange land?
Posts: 21397 | From: Norfolk UK | Registered: Feb 2005
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Barnabas62
Shipmate
# 9110
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Posted
quote:
Originally posted by Golden Key:
Tonight's "The Lawn Chair" episode of ABC TV's "Scandal" is very relevant.
{Slight SPOILERS for series story arc:}
Olivia Pope is a "fixer" in Washington, DC. She fixes the problems of the rich, powerful, and famous. (Occasionally, other people, too.) She's African-American, and the sometime mistress and great love of the white president of the US.
In "The Lawn Chair", there's a Ferguson-type situation, and Olivia winds up right in the middle of it.
Very powerful episode. Looks at all sides. I haven't read the reviews, but I've seen headlines that indicate similar feelings.
It doesn't seem to be online yet. Maybe in a few days?
Was on Sky last night. Dramatically very powerful. It did play very much to the narrative that there is institutional racism in US police forces, that ranks will close to defend an officer who shoots a member of a racial minority, that evidence will be manufactured/tampered with to support the closing of ranks.
BUT
It did give the office of Attorney General a tick, when it comes to supporting the truth of things. And this review strikes me as spot on. Particularly this final summary.
quote:
This is a fantasy less of just and timely government intervention to punish racist violence than of a world where respectability politics actually works.
RL is not so straightforward.
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Who is it that you seek? How then shall we live? How shall we sing the Lord's song in a strange land?
Posts: 21397 | From: Norfolk UK | Registered: Feb 2005
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