Talk:Road/Archive 1

message: I'm a person who's always been confused by, and interested in, the wide array of transit terms. This article would be a good place to address the differences between terms and define terms specifically. What differentiates a street from a road? Or a parkway? How about parkway/highway/expressway/thruway/super-highway etc. Most people think a highway is a divided high volume, multilane route like the interstate highway system, but in fact state and US highways are often regular 2 lane, non-divided roads without controlled access. Im not a road geek, I wish I was though! :) Maybe someone smarter than I in these specifics might want to help polish up this article.
:This would be quite difficult actually. Usage differs between UK and US English, as well as regionally within the US. For example, pavement (US) is, generally, the material roads are made from. In the UK this would be macadam or the like. Pavement (UK) is a paved area reserved for pedestrian and/or bicycle(?) use. In the US these are sidewalks or bikeways/bike paths.
:In the US a "highway" is a significant road maintained by a governmental body. "Significant" need not mean high-volume, it does mean important to connect significant places. There is the US Highway system, and US 66 was two lane for much of its fabled length. Here however, one trips over "route" which is often used when identifying a highway - hence "Route 66" for "US Highway 66." To the FHWA, interstates are "interstate routes" on the "federal aid highway system". Counties and states also maintain their "highways."
:The origin of the word "highway" is probably pertinent as these were historically raised above the surrounding terrain to facilitate drainage. These are tougher to build and costlier to maintain, hence the need for government support, even if only authorizing a toll road. "I'll take the high-road and you take the low-road, and I'll get to where-ever it was in Scotland 'afore ye."
:Other words are equally problematic. "Boulevard" in Michigan is a specific type of median-divided arterial. Left turns, the "boulevard left" in Detroit, involves going past the intersection in question, making a U-turn at a specially designated signalized location, returning to the intersection, and making a right. (This is the simplest high-capacity left turn layout available now, but does require real estate for the median.) In Chicago, a "boulevard" is one of the various tree-lined arterials connecting the various city parks created per the Burnham plan. Here left-turns are standard left-turn lanes.
:US transportation engineers do formally differentiate between roadways based on traffic and use.  These are:
::*Local Roads and Streets — Provide access to adjacent land (<500 vehicles per day)
::*Collectors — Carry traffic and provide access to adjacent land (8,000 - 10,000 vehicles per day)
::*Arterials — Carry intraurban traffic for more than one mile (<25,000 vehicles per day)
::*Principle Arterials — Carry intraurban traffic for several miles (<40,000 vehicles per day)
::*Limited-Access Highways/Freeways — Carry intraurban traffic for long distances and intercity traffic (40,000 vehicles per day and up.)
:"Super-Highway" isn't a technical term, but could easily describe freeways with ten or more lanes carrying 200,000 vehicles per day and up. (I've seen traffic counts in the 300,000 ADT range. I-90/94 Dan Ryan Expressway in Chicago.)
:An interesting place to go for background, although it won't clarify all the nomenclature and the perspective is American, might be the Standard Handbood for Civil Engineers, McGraw-Hill.  There are chapters on "Community and Regional Planning" and "Highway Engineering."
:MARussellPESE 19:38, 31 October 2005 (UTC)
thread_title: Terminology Needs Work 

message: The photo of the airport road with a jet being towed across is certainly interesting and entertaining, but is it necessary or truly add value? --Dpr 04:21, 26 September 2005 (UTC)
replies: text: Yes, it adds value - Adrian Pingstone 14:28, 2 February 2006 (UTC)
thread_title: Photo

message: User:Wbfl keeps deleting this section:
:However, even those countries with stricter standards suffer from increasing levels of truck traffic, which is mainly responsible for road damage (see below).
:On any road, the load per vehicle axle passing over it is mainly responsible for the amount of wear. Since the effective wear done to the road is roughly proportional to the 4th power of vehicle weight, truck traffic almost always is the exclusive 'real' cause of road damage.
:In an example, a hypothetical car weighs half a ton per axle. A truck also travelling on the same road weighs in at 2 tons per axle. The truck causes 256 times the wear of the car (4 times the car's axle load, with a power of 4, yielding 4×4×4×4 = 256), and actual trucks can have even higher axle loads.
This may or may not be true - do we have any sources for this? Do we have any verification that wear is related to the 4th power? If this section is to remain intact, there needs to be some back-up for the claims. On the other hand, the text should remain in place until we decide what to do with it, since it is a fairly large chunk of text, and personally, it sounds reasonable. Graham 06:36, 11 October 2005 (UTC)
replies: text: Most of the discussion so far has taken place at User talk:Wbfl for reasons known only to him. I have located the source for this and amended the article accordingly. Please feel free to weigh in if you have anything to add (here though please!). Graham 05:59, 12 October 2005 (UTC)
replies: text:  I've amended that section.  I'm going by on the AASHTO ESAL (= 18 kip equivalent single axle load) factors compiled on page 296 of the textbook "Pavement Analysis and Design" by Yang H. Huang.  2 kip single = 0.00018, 8 kip single = 0.0343, 36 kip tandem = 1.38.   Works out to 0.00036 ESALs per typical pasenger vehicle, 2.79 ESALs per typical 18-wheeler for a ratio of 1:7800.  ESAL calcualtions are not as simple as raising the axle weight to the fourth power and dividing by 18 kip ^4 .  Axle spacings (single, tandem, tridem) have a large effect, and pavement structural capacity and terminal serviceablilty have a smaller, but significant effect.  Those numbers I used are for SN=5 and pt = 2.5 - for the purpose of this article I think they can be omitted.  Toiyabe 17:09, 9 May 2006 (UTC)
thread_title: Point of contention?