The term "parclo" appears in 66 articles in the SABRE Wiki without explanation.

Given that the SABRE Wiki aims, I would hope, to be a useful resource for the non-specialist reader and not just "road freaks", could I invite those with expertise in the area of road-junction design to write an explanatory article on this and other terms for junction types as used in our pages?

Incidentally, is the term "parclo" actually in professional use in the UK and/or Ireland? My own researches seem to indicate that it is, in origin at least, a Canadian term.

Really there should just be a link to CBRD's interchange explanations, rather than duplicating the information.

It needs to be filed under "SABRE Terminology" if put anywhere.

Edit: have I really done 16,000 posts?!

I picked up most of the terminology I use for junctions from a friend who was a civil engineering student. Following him, I say "half cloverleaf" (or occasionally some other fraction than a half).

Edited to change "for" to "from".

Parclo is not a term I recall seeing in any UK official documents. I'd probably go along with wrinkly's term, 'half cloverleaf'.



I reckon Bryn is the SABRE Committee equivalent of Mrs E Adams

Cheers,

Simon

Mrs Trellis, more like.

You could try, but I don't have a page describing a parclo.


I've heard half-cloverleaf too, though I prefer "folded diamond". This type of junction is listed on CBRD under "diamond" as a variant.

The designers of the Preston Bypass, who installed the first motorway example at Samlesbury, referred to it as a "double-U" junction.

What exactly IS a parclo? I certainly wouldn't have defined the original motorway junction as one - it's a folded dumbbell. Many other parclos are clearly folded versions of other types.

Should we just abolish the term and use 'folded xxx' based on how the sliproads connect to the other roads in the junction?

If I'm not mistaken a true parclo is a cloverleaf with just two of the inside loops instead of four. A similar junction with three loops would also count.

Dare I...

Yep....

Parclo on another less popular website

I thought that this page on the Wiki might be of some help here:Junctions.

I was disappointed.

If no one beats me to it, I might make a stab later in the week, but Stacks, Parclos and Trumpets all confuse me, so it'll be off to CBRD, or even what Haydn said, if I get that far.

Incidentally, can the Junction Box be used to pick out the 'type' for a Category, I think this happens with other data, but Category:Roundabout doesn't exist, and Category:Roundabouts only has one entry.

OOOH! (Getting exicted now) I've found some information in here: Category:Road_Features Could do with padding out, and properly linking together though.

Parclo does appear in some official documentation--if memory serves, the Caltrans design manual references standard interchange types as parclo-A, parclo-B, etc. according to ramp configuration. I wouldn't recommend using "folded" as a substitute for parclo because there are some types of parclo which are not conveniently explained as foldings of another interchange type, such as this:

http://maps.google.com/maps?q=Bakersfie ... 18&vpsrc=6

Yes, it can be done, but you're very reliant on what people type, as it'll try to go in the exact category of whatever someone's put there.

For example Churchbridge would currently end up in Category:Magic Gyratory variant, which doesn't exist.

Fair point (Steven). I guess manually adding more general categories at the bottom is the only way round that. More tediousness!

I still think it's worth putting together some sort of structured junction descriptions though, as at the moment anyone wanting to know what a Parclo is (myself included) either needs to make an educated guess or head off to Google for an answer.

{{Member Site|http://www.cbrd.co.uk/interchanges/|CBRD}} needs to go at the top!