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|Single-Point Urban Interchange (SPUI)|
What is a Single-Point Urban Interchange?
A Single-Point Urban Interchange (SPUI) is a new type of interchange for Michigan. 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.
Since 2004, MDOT has built four of these interchanges:
M-6 and Kalamazoo Avenue in Kent County, completed November, 2004
US-23/M-59 interchange in Livingston County, completed December, 2004
I-96 at Beck Road in Novi, Oakland County, completed October, 2005
I-94 at US-24 in Taylor, Wayne County, completed, December 2005
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
Traffic movement though a SPUI
To see how traffic moves through the Beck Road/I-96 SPUI, see this traffic diagram and the diagram of pavement markings. You can also view a video (4MB) simulation of traffic moving through this interchange.
More information about SPUIs
You can find more information at these sites: