Diverging diamond intersection number two in the Chicago region is opening over the course of a week at I-90 and Elmhurst Road:

Essentially, “northbound and southbound vehicles take turns crossing the intersection,” Garrett explained. “They’ll cross over to the other side, which makes all ramp movements unrestricted. There’s no opposing traffic when turning onto I-90 ramps, which means unopposed left turns and unopposed right turns.”…

On Monday, it will switch to two lanes, and two rebuilt I-90 ramps carrying vehicles to and from the east will reopen. Those ramps will handle about 21,000 vehicles daily.

On Tuesday, two new ramps taking traffic to and from the west will debut, accommodating an estimated 12,000 vehicles a day…

Underneath the diverging diamond is a tangle of utility pipes that carry liquids ranging from jet fuel to O’Hare International Airport to drinking water for suburban communities.

The article notes that only a few motorists had trouble on the opening day.

Looking forward: how many of these can we expect to see in coming years or are these a highway interchange fad? The first diamond interchange in Naperville has had some success – see this earlier post. But, drivers tend to be fussy about changing the roadways, whether with a new interchange or through introducing roundabouts. And, I imagine few residents would be happy to rip out old intersections just to put in a new pattern (think of the costs as well as the lost time to increased congestion). Perhaps we might see a few more of these over the next ten years or so but I don’t think they will become the new normal (which also might decrease people’s comfort with them if they encounter them infrequently).