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First diverging diamond interchange to open in north Phoenix this weekend

The new intersection at Happy Valley Road and Interstate 17. (ADOT Photo)

PHOENIX — Arizona’s first diverging diamond interchange is set to open in north Phoenix this weekend.

The new interchange, located at Interstate 17 and Happy Valley Road, will debut Sunday, according to the Arizona Department of Transportation.

The diverging diamond intersection design allows motorists to cross over and use the other lane, crossing the left side of Happy Valley Road bridge over I-17.

The change also allows drivers to make direct turns onto the freeway on-ramps without crossing in front of opposing traffic.

The goal of the redesign is to reduce the number of collisions exiting and entering the highway while improving the flow of traffic over the highway’s on-and-off-ramps.

The interchange replaces two roundabouts that had been in service for two decades, according to the release.

The interchange is part of ADOT’s three-year, $50 million construction project, which includes the reconstruction of interchanges at Happy Valley and Pinnacle Peak roads and the widening of the highway by one lane in each direction.

The reconstructed interchange will reopen in a temporary setup as part of a phased reopening strategy. There will be lane restrictions in place on the Happy Valley Road exit at I-17 until the work is completed later this fall.

The majority of the reconfigured interchange will open in a temporary configuration as part of a phased plan. Some lane restrictions will be in place on Happy Valley Road and the I-17 exit ramps until all work is completed later this fall.

The project is funded by the Regional Transportation Plan that Maricopa County voters approved in 2004.

The highway’s ramps will be closed from 9 a.m. Friday to 5 p.m. Sunday, with Happy Valley Road being closed in both directions approaching I-17.

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