Diverging Diamond Interchange Keeps Traffic Moving Quickly
Ever been driving on the road and had some one make an unprotected left turn in front of you, cutting it too close for comfort? With this innovative concept for regulating traffic, you won't have to think about it. The diverging diamond interchange (DDI) traffic pattern has drivers temporarily switch sides of the road in order to keep traffic moving more quickly.
The idea of the design is for traffic to merge to the opposite side of the road before passing over (or under) the freeway. Using only 2 signaled intersections, each direction crosses over one another before passing the interchange.
No More Risky Left Turns
Flipping the side of the road you're driving on allows for unimpeded left turns. You won't have to worry about un-attentive drivers turning right in front of you, or sitting in traffic for what seems like an hour waiting for the line of cars in front of you to make a left turn across incoming traffic.
Check out this computer simulation showing how the divergent diamond interchange works:
When will we start to see the implementation of DDI's on U.S. roads? The first and only diverging diamond interchange in the United States is located in Springfield, Missouri at I-44 and MO 13.
Are they planning to build more? According to Steve Porter, MoDOT senior public relations specialist, "Other DDI's are currently under study at the Ontario Ministry of Transportation, the Oregon, Virginia, and New Mexico Departments of Transportation, and the City of Baltimore, Maryland." (Source) I've also heard that they are thinking about building one in Colorado.
The reason more haven't been built? The arguement that has been made is the DDI would be too confusing for drivers, which would cause them to switch lanes and cut each other off. But I think it's foolish to assume it won't work; after some getting used to, these could be very helpful in major traffic interchanges across the US.
If you want to see more, the Missouri Department of Transportation has provided photos of the DDI in Springfield, Mo. Want to know what it's like to drive through a DDI? Here's a video of it:
I'd definitely like to see some DDI's on the West Coast, I don't think they would confuse too many poeple. Would you like to see more DDI's on the roads? The idea sounds good on paper - do you think they could work?