Talk:Three-way junction

In the UK at least, it is permissible to turn across a double white line.


 * 108 Double white lines where the line closest to you is solid. This means that you MUST NOT cross or straddle it, unless it is safe and you need to enter adjoining premises or a side road. (UK Highway Code)

(Don't put this text in the main Wikipedia without checking with the Stationery Office.)

If turning right were forbidden, there would be a specific "no right turn" sign (or a full central reservation).

volume of asphalt
iwant to compute the volume of asphalt of 50mm layed at a t-junction. 208.78.63.48 (talk) 09:58, 12 May 2010 (UTC)

Right-of-way prose is scattered
See Wikipedia talk:WikiProject Highways. --Chaswmsday (talk) 23:33, 20 September 2012 (UTC)

Addition of continuous-flow intersection and three-way interchanges prose
Copied from User talk:Chaswmsday:

''Hi Chaswmsday, I added some knowledge into the article. Would you review my english language skills a little bit. Thank you so much. https://en.wikipedia.org/w/index.php?title=3-way_junction&diff=570793952&oldid=568959088 --Hans Haase (talk) 11:10, 30 August 2013 (UTC)''

End copy. --Chaswmsday (talk) 16:31, 9 September 2013 (UTC)


 * Hi Hans! Sorry it took so long to respond. I went out of town for a couple of weeks over the US Labor Day holiday, and basically ignored Wikipedia over that time!


 * Although a 3-way junction could be implemented as a CFI, it's been, as far as I know (AFAIK), so far used only at ordinary 4-way crossroads. Thus, I'm not sure prose about CFIs is appropriate within this article.


 * However, reading over the CFI article's prose, I find that article kind of dances around the crossing of oncoming traffic and doesn't state that point clearly, IMHO. Perhaps some of your additions to 3-way junction should be incorporated instead into CFI.


 * Also, I'm not sure 3-way junction needs to say that a three-way interchange could improve performance. Again IMHO, it's likely understood & stated in other articles that grade-separation often improves traffic performance (of course, at a cost...)


 * I've watchlisted way too many articles. Gotta go check on some more. :( Let me know what you think. :) Later! --Chaswmsday (talk) 16:55, 9 September 2013 (UTC)


 * CFI is in a 3way-IS in Accokeek, MD. See the map! This has also the continous-green north to southbound. There's no XING PED. CFI and High-T increase the total VPH of the IS. In the DE-WP article of the CFI, I discovered it completely (in 4way cfi, 2 displaced left turn lanes, conficting way groups are from 4 to 3, (see most of the exsamples) in a 4way cfi with all 4 displaced left turn lanes coflicts are form 4 to 2, in a 3way cfi, only 1 displcd ltls reduces conflicts from 3 to 2). Afaik, this are most efficient methodes to increase VPH saving costs and space. All kinds of intersections should be compared. A full grade separated interchange provides free flowing traffic. The only bottleneck is waving traffic. Cloverleafs have it inside, Stack interchanges have the weaving before and behind the intersections, spread out over longer way. Here's an other one, using just 2 conflicting directions:
 * 49.463815,8.505955 3-way superstreet or at-grade trumpet ? In Mannheim, DE, EU
 * 49.488973,8.512526 a superstreet in Mannheim, DE, EU (4way) --Hans Haase (talk) 18:20, 9 September 2013 (UTC)

Picture
I don't suppose there's a better picture available? The current one doesn't actually show the three way junction, as one of the roads is completely obscured by trees. It seems a bit silly considering how easy it should be to get a better picture. - Alltat (talk) 12:54, 5 March 2014 (UTC)

2018 (from another person): I found a better one and replaced the old one.

Definition of Y junction vs T junction appears to be incorrect
I am from Australia, where the term T intersection refers to roads where two roads form a straight line and the intersecting third road is perpendicular. It retains the term regardless of the size or traffic flow of each arm. Even where the road is broad and heavy traffic performs a right-angle turn and only a minor, low traffic road continues straight.

A Y intersection covers all other three-way junctions where no two roads form a straight line. The rare and un-named exception to this is where both angles of intersecting roads add up to less than 90 degrees.

I believe the opening paragraph should read similar to this:

A 3-way junction (or 3-way intersection) is a type of road intersection with three arms. A T junction (or T intersection) is formed when a straight road is intersected by another road approaching at roughly 90 degrees. A Y junction (or Y intersection) refers to all other angles of intersection where no two roads form a straight line.

I have not updated the article, but open this for discussion, because my experience is limited to one country.

Eltimbalino (talk) 06:15, 10 August 2015 (UTC)