PHOENIX, AZ — Drivers southeast of downtown Tucson will see a major step forward in an interchange reconstruction project as crews pour the concrete bridge deck on the new Houghton Road structure at Interstate 10. The concrete work on the bridge comes as the Arizona Department of Transportation reaches the halfway point of a $24.4-million project to rebuild the interchange.

While drivers have experienced several temporary ramp and lane shifts during the project, the concrete pour will allow drivers to see the bridge’s final driving surface come into view.

This summer, traffic on Houghton Road will move from the existing two-lane bridge to the new six-lane structure. Motorists will cross I-10 in a temporary lane configuration for several months while crews demolish the old bridge and complete building new ramps on the east side of the interchange.

Throughout the project, drivers should expect periodic traffic shifts, along with some overnight and weekend restrictions.

The project, which began in August 2020, is scheduled to be complete by the end of 2021. It will feature southern Arizona’s first diverging diamond interchange, a significant change from the existing diamond interchange.

When the diverging diamond configuration is in place, traffic on Houghton Road will make a temporary shift to the left side of Houghton Road while crossing I-10. This allows for left turns onto the entrance ramps without waiting at an additional traffic signal. This design promotes safety because drivers turning left do not cross traffic while entering the on-ramp.

More than 115 diverging diamond interchanges are in use in the U.S. Arizona’s first full diverging diamond interchange opened in late 2020 at Interstate 17 and Happy Valley Road in Phoenix.