New $1.7B Ariz. freeway consists of half diverging diamond, double roundabout (VIDEO)

(Arizona DOT word: For the reason that launch of this video in January 2017, the Dobbins Highway interchange has been redesigned. The freeway will now go over Dobbins Highway. )

Together with being the biggest freeway development undertaking in Arizona historical past, the brand new 22-mile South Mountain Freeway round southwest Phoenix incorporates some attention-grabbing options, together with a double roundabout and two half diverging diamond interchanges.

The $1.7 billion undertaking, often known as Loop 202, supplies a bypass to busy Interstate 10 at downtown Phoenix. The brand new freeway consists of three common lanes and one HOV lane in every course. Work on the undertaking started in 2016 because the state’s first public-private partnership for freeway development, in response to the Arizona Division of Transportation. A ceremony was scheduled for December 18 for the freeway’s completion.


Modern interchanges

A drawing of one of many two half diverging diamond interchanges integrated into the South Mountain Freeway. Credit score: Arizona DOT

The design consists of two half diverging diamond interchanges. These intersections differ from a full DDI in that one journey lane doesn’t lengthen previous the interchange, limiting entry to solely three sections, in response to the Arizona Division of Transportation. AZDOT says the interchanges enhance security by eliminating cross-traffic left turns, enable extra autos to stream by means of the interchange and price lower than full DDIs.

The freeway additionally features a double roundabout that AZDOT says will scale back crashes and enhance visitors stream. Drivers approaching the roundabout should scale back velocity and yield to visitors already within the roundabout. When it’s protected to enter, drivers can exit east or west or re-enter the freeway.

The freeway additionally cuts by means of the environmentally delicate South Mountains. AZDOT mentioned this was carried out with minimal ecological impression and with 5 crossings beneath the freeway designed for wildlife, pedestrians and cyclists.


Forward of schedule, beneath funds

A map of the South Mountain Freeway’s route. Credit score: Arizona DOT

AZDOT partnered with non-public improvement crew Join 202 Companions. Join 202 was not solely liable for the design and development of the freeway, however for sustaining the freeway for the following 30 years.

The company mentioned the partnership’s construction allowed the undertaking to be accomplished three years faster as a result of the 4 segments of the freeway could possibly be constructed concurrently. That additionally value $100 million lower than a standard contracting methodology, AZDOT says.

Join 202 Companions consists of Fluor Enterprises, Granite Development and Ames Development and freeway upkeep contractor DBi Companies.

Credit score: Arizona DOT