The Single Point Urban Interchange (SPUI, pronounced Spoo-ee) is a relatively new design that controls several directions of traffic with a single set of traffic lights.  The goal is to move lots of traffic without taking up a lot of space in a dense location. Read more about SPUI design at Wikepedia.

Consequences for Bike/Ped
While SPUIs are great moving cars, they are not so good for bicyclists and pedestrians. It can be challenge for a bicyclist to get through the entire intersection before the light changes.  Because the traffic lights are mounted in the middle of intersection, the bicyclist cannot see when the light changes and traffic begins coming from a different direction. Pedestrians are usually not able to get through the intersection with one green light.  It can take up to four cycles to walk through the entire length of a SPUI.

Missouri SPUI Study
The Missouri Department of Transportation and the University of Missouri – Science and Technology (Rolla) conducted a study on SPUIs that recommended against using them on routes with bicycle and pedestrian traffic. Read the Missouri SPUI Study.

Locally
The first SPUI in the KC metro area is at 87th Street over I-35 in Johnson County, KS. This intersection is quickly becoming infamous as an un-friendly place for bicycles and pedestrians. Many bicyclists resort to riding on the sidewalk, despite the risks inherent in that choice.

The next SPUI currently being planned is in KCMO at Front Street and I-35/I-29, as part of the Paseo Bridge replacement project.