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April 29, 2010

Comments

madmax

Inspector,

Good to see you blogging again. I hope you continue.

I remember a long and very interesting debate on immigration you had with Galileo Blogs. In that debate, I think you made a side point that there were some cultural considerations to immigration that needed to be taken into account. Am I right about that?

Related to this, do you think there is a danger, in our multicultural leftist nation, from mass Hispanic immigration? For example, if tomorrow we woke up and there were 200 million more Hispanics in America, how socialist would we become in short order? Immigration is a tough issue. The common Objectivist argument for open mass immigration seems problematic to me.

Lastly, some conservatives are saying that if this Arizona law survives it will cause other states to adopt similar legislation. The reason is that illegal immigrants are going to move from Arizona to other states. No state (other than delusional Leftist ones) will want to be a magnet for illegals. So this Arizona law may be a move in the direction of a radical slowdown in immigration much like what happened in 1924. Do you think that is the likely outcome?

Regards,

MM

Inspector

Hello MM,

I don't remember all of the details of that debate - it was quite long - but it's likely that I made a side point like that.

I do think that mass immigration from a culture hostile to Capitalism is a real danger for a mixed country such as ours. It would likely be a non-issue for a true Capitalist country with actual, limited government.

That said, I believe our current immigration policy is in bad need of reform - it only fosters a black market which is very bad for everybody except the criminals.

The common argument I hear from many Objectivists seems to take a stand on a principle while not addressing our current context. That seems to me like a less than ideal approach.

The outcome of this is anyone's guess at this point. Conservatives don't have the support to make a counter-push like this last. And if they do, a pox on them - they should be spending that energy fighting Obamacare and this new business-strangling thing that they've just declared surrender on.

Antacid

Not like the brazen giant of Greek fame,

With conquering limbs astride from land to land;

Here at our sea-washed, sunset gates shall stand

A mighty woman with a torch, whose flame

Is the imprisoned lightning, and her name

Mother of Exiles. From her beacon-hand

Glows world-wide welcome; her mild eyes command

The air-bridged harbor that twin cities frame.

"Keep ancient lands, your storied pomp!" cries she

With silent lips. "Give me your tired, your poor,

Your huddled masses yearning to breathe free,

The wretched refuse of your teeming shore.

Send these, the homeless, tempest-tost to me,

I lift my lamp beside the golden door!"

Antacid

"Conservatives don't have the support to make a counter-push like this last. And if they do, a pox on them - they should be spending that energy fighting Obamacare..."

To do what? Replace it with their own version of health care "reform?"

I really can't see any "conservatives" making any kind of counter-push because they seem to lack the desire for any real, meaningful immigration reform. Most of the people I've heard from who identify themselves as conservative seem to be in favor of militarizing the border with Mexico and maintaining the status quo with regard to our immigration policies with hispanic people.

I guess at this point I should seek clarity. By conservative, do you mean a person who truly believes in the good and necessity of a limited government which exists to secure the rights of its citizens, or do you refer to the closet statists who pass themselves off as conservative (John McCain, et. al.)?

Antacid

Oh, by the way, I see no rioting in the streets.

Inspector

"To do what? Replace it with their own version of health care "reform?""

Heh, good point. And yeah, I meant the mainstream of the movement, who I don't see doing anything useful.

Oh, and sorry for the delay in response.

Antacid

The following is a bit long. Be forewarned:

I also feel compelled to mention a thing or two about speed limits. First things first, however, I must give some credibility to what I'm saying. Just last week, I completed a BSE in Civil Engineering at ASU, and my degree program included two courses in transportation and roadway design. While this by no means makes me an expert, I do feel that it gives me a better perspective than the average Joe. In addition, I have a friend who works as a field engineer for the Arizona Department of Transportation, and we've spoken on a few occasions about speed limit criteria.

First of all, I am assuming that you are under the impression that speed limits on most roadways are determined more often by political nonsense than by the speed that most cars can safely navigate the roadway. According to my instructors, this is sadly true in many cases, especially within city and township limits. In cases where this is not true, however, one thing that most people do not realize is that speed limits are not only determined by vehicle performance, but they are based on a number of factors such as:

Sight Distance
Driver Capability
Crash Barrier Capacity
Curve Radii
Clear Zone Width
Vehicle Performance / Vehicle Types
Accident History

Most of the time, vehicle performance is not the limiting factor. It's usually one of the other factors such as clear zone width, sight distance, or driver performance.

With regard to driver performance, a poll was given asking drivers to rank their driving ability and habits. Somewhere between 70 and 80 percent of the respondents considered themselves to be among the top 10% of all drivers in the U.S. It can therefore be reasonably concluded that the majority of all drivers in the U.S. have grossly overestimated their driving ability. This, however, is more of an aside than anything else.

As mentioned before, sight distance is one of the more often used criteria in determining a speed limit. In particular, agencies are most concerned about stopping sight distance (SSD). It is defined as the sum of the distances travelled as the following occurs:

- Visually perceive an object in the road.
- Make a determination that the object is an obstructive threat.
- Make a determination that the vehicle must be stopped to avoid hitting the object.
- Make the action to begin stopping the vehicle (usually move the foot over to the brake and press down)
- Decelerate under braking power to a stop.

Some assumptions must be made to determine this distance, and these assumptions are generally either given by AASHTO or by the relevant transportation agency responsible for the roadway. Usually it is assumed that the first four items require approximately 2.5 seconds. This is a somewhat conservative value, but not quite as conservative as you'd probably like to think. The deceleration is assumed to take place at a constant rate that is given by AASHTO or the governing transportation body. This rate is also somewhat conservative as it is based upon less than ideal pavement and weather conditions and lower braking efficiency coefficients typical of larger trucks. After all, one speed limit usually must be chosen for all vehicles. As you can imagine, these stopping sight distances are fairly standard across all projects, so graphs of stopping sight distance versus speed and roadway slope are commonly provided by transportation bodies and used across many projects.

The person determining a roadway segment's speed must determine the point in the segment that gives the least amount of sight distance to a 2 ft. tall object in the road. This value is then compared to the aforementioned graph to determine a speed based on sight distance.

The clear zone width is the distance from the edge of the roadway to the nearest obstruction (trees, light poles, billboards, etc.). The idea is that if a vehicle loses control, this zone gives the vehicle adequate distance to at least slow down enough to minimize the risk of having a fatal collision. Different widths are specified based on the speed of the roadway segment and sometimes the soil and vegetative ground cover material in the clear zone. Sometimes a roadway must pass near an object that would be too costly to move or demolish (important building, mountainside, property for which exercising state sponsored theft -- oops imminent domain -- would be politically difficult, etc.) and the clear zone width is determined by that obstacle. This can then become a determining factor for the speed of the roadway.

This final common factor was told to me not in class but by my friend at the Arizona Department of Transportation. Most often the speed of an urban freeway or highway is determined by the capability of the crash barriers in place. The goal is to keep the speed below the maximum speed that a crash barrier can prevent an out-of-control vehicle from crossing over or smashing through the barrier.

All of these factors are considered and the maximum speed limit for the roadway segment is set as being the lowest acceptable speed determined by each of the above factors. Of course, the posted speed limit is set a little lower than that because it is not wise to have vehicles operating right at the threshold of what is safe.

I hope this gives you at least a bit more of an appreciation of why speed limits are set how they are. Sometimes it may seem like the speed limit is too low because the roadway curves do not challenge your car's handling, but the speed limit in those cases may be based on one of the other factors above (or sometimes even something else).

Finally, understand that these are the factors considered for highway design in an open area. When designing surface roads with intersections, driveways, shopping centers, etc., other factors will also come into play.

Inspector

"First of all, I am assuming that you are under the impression that speed limits on most roadways are determined more often by political nonsense than by the speed that most cars can safely navigate the roadway. According to my instructors, this is sadly true in many cases, especially within city and township limits."

Precisely so.

As one particularly glaring example I can think of, there's the fact that Glendale surface streets are 40 mph while all other towns in the valley - with the exact same streets - are 45. This accompanied by smarmy and insulting signs everywhere beseeching, "it's our town; please SLOW DOWN." It doesn't take a rocket scientist - or even all of the complex training and factors you list above - that there's a political busybody responsible for that one.

Another example is the dreaded 55 I see prominent in certain states - driving through on the exact same highways linking to them going 65, 75, or even 80... slowing to 55 is a sanity-testing crawl when directly contrasted in that manner, with the famous political motivation responsible from back in the '70's.

Inspector

Oh, and don't get me started on when those sightlines you refer to are seemingly deliberately obscured by cosmetic crap like "pretty" bushes and other such nonsense that some politico mandated. (at least the sahuaro/scrub combo in AZ is fairly non-intrusive)

Oh - and maybe you'd be a good person to ask - is there any redeeming value to those islands and high curbs they often build (at great expense and blocking of traffic during construction) in the middle of surface streets where once existed a center median that could serve as a turn/turn-around/emergency lane? (Besides, I mean, to get in the way of fire trucks and ambulances)

Antacid

I hate those islands. I especially hate how you are restricted to turning wherever the city deems that you should be allowed to do so.

I've been told two things about the islands. The first is that they're a safety feature on lower speed roads to prevent a vehicle crossing into oncoming traffic. I've also heard they're less safe because a vehicle that runs into them at sufficient speed, the curb will destroy the steering, thus making the car completely out of control.

I have a friend who actually has to drive past his neighbohood about a quarter mile and make a u-turn just to get to his house. This is because the city put in an island but didn't bother with a left turn opening for his street.

Antacid

Sorry, I need to correct the last sentence of the second paragraph. It should say:

I've also heard that they're less safe because a vehicle that runs into them at sufficient speed can have its steering destroyed by the curb, thus making the car completely uncontrollable.

Antacid

Sorry for adding another comment about it, but my previous comment didn't seem to completely address your question.

First of all, there was no mention of the use of raised medians on local roads in the ADOT manual that we used for my highway design course with only one exception. Any local (surface) road that intersects a highway is required to have a raised median approaching the intersection when it is feasible to construct one.

There is potentially one redeeming quality to the center medians, but it has nothing to do with managing traffic flow or safety. I'm not completely sure about this (and I'll try to ask around when I attend my first APWA meeting), but constructing the curbing and landscaping the median might be cheaper than paving that area. Most asphalt used in flexible pavements is a petroleum product, and it varies in cost just like gasoline (some asphalt used occurs naturally and can be found in some lake bottoms or former lake bottoms -- this is the creme-de-la-creme). Once it reaches a certain price it might become cheaper to set up forms and pour curbing to create a raised median than to pave that area (or replace existing pavement in need of repair).

However, my transportation engineering professor (Dr. Simon Washington) told us that most raised medians are put there for aesthetic reasons, and he acknowledged during this lecture that they greatly interfere with the movement of emergency vehicles.

Inspector

Hm, okay. I pretty much figured that, but it was worth asking.

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