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Single-Point Urban Interchange (SPUI)

What is a Single-Point Urban Interchange?
A Single-Point Urban Interchange (SPUI) is a type of interchange. In a SPUI (pronounced "Spooey"), a single traffic signal at the center of the interchange controls all left turns. Drivers make opposing left-turns at the same time under the protection of this signal.

What are the benefits of a SPUI?

  • Can be constructed where there would not be room for a standard interchange--ideal for urban areas
  • Can allow more vehicles to make a turn and clear the interchange in one traffic signal cycle
  • Can be coordinated with cross-street signal systems
  • Allows long, gradual turns so larger vehicles have more room to navigate

Examples of Traffic Movement Through a SPUI

More information about SPUIs
You can find more information at these sites:

Related Content
 •  Roundabouts
 •  Michigan Lefts
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