I found a video that helped me to visualize this design better than I could from the article. It is a 4 minute long animation of the interchange in action from the Missouri Department of Transportation found on this page: http://www.modot.mo.gov/springfield/major_projects/Greene/I-....

And here is a direct link to the video (13MB): http://www.modot.mo.gov/springfield/major_projects/Greene/DD...

There are also some more pictures: http://www.modot.mo.gov/springfield/major_projects/Greene/Di...