A “spaghetti junction” is a nickname that has been used to describe a complicated, or heavily intertwined interchange where the crisscrossing roadways resemble a plate of spaghetti.

Seen above is the original spaghetti junction, located in Birmingham, England. The Gravelly Hill Interchange is junction 6 of the M6 motorway where it meets the A38(M) Aston Expressway.

Journalist Roy Smith first used the phrase in a newspaper article in 1965 to describe the interchange while it was still under construction. You can find a list of other notable spaghetti junctions on Wikipedia.