Highway 40 Insight

Weather, Traffic, SPUIs, and DDIs

It seems that it’s not just thinning-hair computer science majors (i.e. myself) that have an interest in the area’s traffic. It looks like Fox 2’s own thinning-hair weatherman, Chris Higgins, has taken a liking to traffic in addition to the area’s humidity and cold fronts.

Chris posted to his blog recently about the proposed interchange at I-270 and Dorsett Road. One option being considered is a Single Point Urban Interchange (SPUI), used at Olive and I-270 and also planned for the Lindbergh, Hampton, and Kingshighway interchanges on Highway 40. Once considered novel, the SPUI is becoming much more commonplace in the St. Louis area.

The second option is completely unconventional. Called a Diverging Diamond Interchange (DDI), this interchange actually has you driving on the “wrong” side of the road under the overpass. Not to mention it’s never been built in the United States. There’s a wikipedia article to explain a DDI, but Chris also has video of MoDOT explaining this very unique intersection. (You can view Chris’s full post here). MoDOT has also posted diagrams of the proposed SPUI and DDI.

This isn’t the first time that MoDOT has been pushing the envelope with traffic designs. Yesterday’s Post-Dispatch highlighted another interesting intersection, the continuous flow interchange, that just opened at Highway 30 and Summit Drive.

This entry was posted on Thursday, November 1st, 2007 at 6:00 am and is filed under General, I-270. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.