Talk:Three-point turn

(Turn/Turning in title)

Is this a British term? To me, as a primarily American English speaker, "turning in the road" could mean taking a right or left turn down a street, or even turning around a hill while staying on the road. There's certainly nothing in American English that would cause this term to exclusively mean a 180 degree term. I'm not saying it shouldn't exist because it's British, but that it should be qualified as such. Jonemerson 07:53 & :53 (two edits w/in the minute), 7 December 2006 (UTC)

I don't know if it is exclusively British, but it is common parlance here in the UK.--Lapin rossignol 18:06, 8 February 2007 (UTC)

I live in N.Ireland and I call it a 3 point turn but my instructor calls it "turn in the road".
—Preceding unsigned comment added by 2007 82.18.172.187 (talk) 15:11, 16 April

"Turn-in-the-road" is the official term for it. It used to be "three-point turn" but was changed to allow for more stages (e.g. five-point turn). Java13690 18:31, 25 June 2007 (UTC)

"Turn-in-the-road" may be official, but I (British) certainly still hear "three-point-turn" a lot more. Maybe that will change as younger drivers come through. 86.136.251.18 03:01, 10 November 2007 (UTC)

   Official where, Java?
--Jerzy•t 14:15, 2 September 2010 (UTC)

In British English it is generally known as a three-point turn, but the Highway Code, law, your driving instructor etc has it as "turning in the road". You are usually asked to make a turn in the road on your driving test, and you can make as many steps as you like, but if the instructor thinks you made too many, you fail. That is to say, take three in a small car, five in a larger (depending on which road etc).Si Trew (talk) 10:11, 4 May 2010 (UTC)^{Duplicate sig added by me, to avoid confusion in the minimal refactoring of dividing the paragraphs of one contrib between two sections concerning the two topics the colleague commented on.--Jerzy•t 14:15, 2 September 2010 (UTC)}

   I must confess to serious confusion as to exactly what is meant in using "Turning" in the title, and in the lead (both of which date from the first revision). I recall British friends, or actors and public figures heard on the media, using "turning" in a way no American would, i guess with the meaning "place at which to turn". Yes, i mean as what sounds to me like a gerund (if i correctly recall the terminology), functioning in a noun role, but a noun that denotes something eligible for being preceded by an article: "We almost missed the turning", or "... at a turning next to an underground station." At least if the sense of "turn" is the one about change of direction, we use the gerund, i think, only to refer to a process or activity: "Turning right in the UK means, for Yanks, taking their life in their hands: why are all those cars acting like they have the right of way?" or "Turning right on red is still illegal in New York City." (I keep wondering whether this difference exists only in the case of "to turn", bcz i can't think of any parallels. Wait, we say "a building", meaning the structure that results from the process of building, and think of that word's relationship to the process of building as more of a pun than a derivation -- is "a turning" like that?)
   Perhaps too much said, just now, but in any case, it leaves me uncertain whether the "turning" in the case of this article might refer to something other than what it sounds like to my ear: "Turning in the road", an article on how to turn in the road, tho we don't do how-to articles. Can it sound to British ears like "Making a turn in the road"? (We do of course say at Wikipedia:Article titles#Article title format that "Sometimes the noun corresponding to a verb will be the gerund (-ing form), as in Swimming." Still, that's made to sound like a last resort, so perhaps that supports my unwillingness to settle for it.
   I think the fact that it is a country's official term is a liability, not an asset. Republic of Macedonia is appropriate, with FYRM the Rdr, but the scope here is not (1) such turns in the UK, nor (2) official doctrines about such turns: the scope should the practical problems they meet and how they solve them. Something like Vehicle-reversing turns may be the ticket, with the lead clarifying that it's doing without intersections (including driveways) and planned turn-around routes that's the focus of the article.
--Jerzy•t 14:15, 2 September 2010 (UTC)

(Programming term)

The following 'graph was originally the second 'graph of a 2-'graph contrib, whose 1st 'graph is now in the "Turn/Turning in title" section.

How I came here is I want to say that metaphorically in computer programming a standard swap is a three point turn "let temp = b, let b = a, let a = temp." That is a fairly standard term, a three point turn there, and I wanted to add that to "Three point turn" but it is a redirect. Of course I can quote sources etc. going back to the sixties, e.g. Brooks, and more modern. Si Trew (talk) 10:11, 4 May 2010 (UTC)

   Great input, thanks; i'm on it & at your talk page, i will solicit more content.
--Jerzy•t 14:15, 2 September 2010 (UTC)

Standard swap embodies such an article, and i've added a {{Redirect}} HatNote Dab to the article accompanying this talk page.
--Jerzy•t 18:49, 5 September 2010 (UTC)

More general vehicles

   IIRC, the article addressed cars specifically, and i've generalized it with

... unarticulated vehicles with reversible propulsion systems...

bcz everything in the procedure would apply to a bicycle with direct drive (or for that matter, gears but no freewheel)! More practically, it applies to farm tractors bcz virtually everything abt the procedures themselves applies that generally -- even with axles of radically different length as shown in the tricycle-like File:RogerTractorLarge.jpg below (tho i hesitate to guess whether the space advantage of the reverse-3-pt extends to those cases).
--Jerzy•t 14:15, 2 September 2010 (UTC)

K-turn from hell

   What the official drill describes is, i think, an easy special case. More or less as i put in my fact tag, this sounds like not an "approved method" for doing K-turns in any situation where a U-turn fails, but a pedagogical tool for preparing drivers for the test on a standard test road that allows far more margin. I can see reasons why that is not an irresponsible approach for driver ed: If you can handle a moderate one, you'll start picking up the rhythm and unconscious logic of the method; when the potentially necessity turning beyond the desired final direction, and then returning to center only when it's obvious you're out of the woods will come naturally and mostly unconsciously.
   But if i am right, it means we have failed at our task of making our description of the real-world process accurate.
   The theoretical situation is this: given a road-width, which vehicles can do a K-turn on it depends on three parameters of the car: width, length, and turning circle. Expressing those parameters as fractions of the road width gives you a 3-D graph of "car design space", with surfaces dividing (perhaps only hypothetical) cars that can make the U-turn from those that require at least a K-turn, and those from the cars requiring higher-order turns, and those from vehicles that have to drive thru without reversing direction. But you can get a better feeling for the range of difficulty, and the consequences of more or less difficult, by some simplifying assumptions: insignificant length and insignificant width. I drew circular arcs around a physical cylinder and parallel lines with a ruler. The ratio between road widths the barely permit a U-turn and barely prevent a K-turn, for my simplification, is about 2.9! If you're relatively close to the U-turn succeeding, your backing takes you toward the opposite curb rather than the original one, and you don't even need to approach the curb in the backing move: you're on your side of the road when your backing brings you parallel, so you just shift into forward and straighten the wheel. As you consider progressively narrower roads, you reach a stage where how far beyond center you have turn the wheel before straightening out and driving away depends on how close to the original wall you backed up. At the edge of needing a 5-pt turn, you back at the full limit of steering, from the opposite curb to the original one, and only if you turn the wheel all the way (past center) back to its opposite limit do avoid hitting the opposite curb a second time, barely skimming past it before steering over to the center of your lane. I'd like to believe that whoever runs driver ed in the UK had bar graphs plotted, showing, for each of a representative sampling of brands and models, how wide the road has to be for the driver to be able to skip the last n sub-steps of the full K-turn process, and concluded that the missing steps interfered too much with getting the remaining steps straight to be worth including them in the official instructions.
   IMO we should acknowledge their version by pointing out where it leaves off, in a complete any-width K-turn procedure.
--Jerzy•t 14:15, 2 September 2010 (UTC)

What is it

This article is about a thing. We have the name of the thing at great detail, what the Canadians name it, and discussion about it here, including a picture of a tractor... but what in Sam Hill IS it? I know about a 2-point turn: drive along, slow down, turn say left, stop up against the curb (1st point), reverse the transmission and the steering, which backs the vehicle across the road and ends up facing opposite the original direction. A 2nd stop (2nd point) and shift transmission into forward and you drive off, having made the equivalent of a U-turn on a road that would be too narrow for it. A THREE POINT turn would add a 3rd stop and reversal, which would leave the vehicle driving off in the original direction. Is that what this thing is? Should not this article offer some definition? Friendly Person (talk) 03:02, 25 February 2012 (UTC)

You may have a point about the name, but yes, it's as you describe. Three elements of travel, but only two points where you stop and change direction. I've added a brief description, source to the Canadian online source. It would be neat to find, or create, a copyright-OK diagram to include. PamD 09:02, 25 February 2012 (UTC)