Have you ever seen a road junction that looks like it has a cloverleaf in the middle? Well, funnily enough they’re called cloverleaf interchanges. But sometimes, they don’t have all four loops and so they’re known as partial cloverleaf interchanges or parclos.
More specifically, a partial cloverleaf interchange is an alteration of the cloverleaf interchange and its freeway-to-arterial interchange design is especially popular in North America and some European countries including Hungary, the Netherlands, and the United Kingdom.
To add another colloquialism to this blog, we also have a parclo variation known as a “dumbell” (due to its appearance) which is a combination of a diamond interchange and the roundabout interchange. According to roads.org.uk, the UK’s first full motorway interchange was a variation on this—or “a parclo with roundabouts”, built on the Preston Bypass and opened in 1958.