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
- I-94 SPUI at Westnedge Avenue in Portage
- Beck Road/I-96 SPUI - View traffic diagram and the diagram of pavement markings. You can also view a video (2.4MB) simulation of traffic moving through this interchange.
More information about SPUIs
You can find more information at these sites: