Interchanges | Roads.org.uk

We all know our way around a roundabout and everyone is familiar with a crossroads. But do you know the difference between the many types of multi-level interchange used on motorways and expressways, or why one might be chosen over another?

This page explores the different types of interchange you'll find all over the UK on limited access roads - roads with flyover junctions that separate fast moving traffic from the local road network.

Visitors to this page might also find the Dictionary helpful.

Motorway to road interchanges

Diamond

Conventional, basic motorway-to-road connection.

Dumbbell

Halfway between a diamond and a roundabout interchange.

LILO

A junction with no bridges and not much choice if you're on the side road.

Roundabout Interchange

The true British interchange.

Three-way interchanges

Fork

One way on and one way off: a fork in the road.

Triangle

Three levels of road, three roads connected, three ways to build it.

Trumpet

The simplest free-flowing three-way connector.

Four-way interchanges

Cloverleaf

Four symmetrical loops — it's impossible to miss a cloverleaf. If you can find one, that is.

Four Level Stack

It is big, and it is clever.

Partially Unrolled Cloverleaf

A clever improvement on the cloverleaf.

Three-Level Stacked Roundabout

A cheap and cheerful way to fully grade separate two intersecting roads.

Whirlpool

Free-flowing, resizeable and also quite pretty.

With thanks to Lazlo Horvath for information on this page.

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