PHOENIX – On Monday, August 24, the Arizona Department of Transportation will begin work on a project to improve access to Interstate 10 at Houghton Road.
The new $24.4 million interchange includes a traffic design called a diverging diamond. The diverging diamond design requires drivers to make a temporary shift to the left side of Houghton Road while crossing the freeway. This allows for left turns onto entrance ramps without waiting at an additional traffic signal.
ADOT traffic engineers chose this design because it can handle higher traffic volumes in the growing southeast Tucson area, where traffic is expected to increase by as much as 50 percent by 2045.
The new Houghton Road bridge will feature six lanes of traffic, compared with two lanes on the existing structure. Also, the project will improve access for pedestrians and bicyclists. ADOT has developed a construction plan that minimizes traffic impacts by building the new Houghton Road bridge while traffic continues to use the existing structure.
During the first week of construction, traffic impacts are expected to be minor as crews begin clearing areas in the work zone and mobilizing equipment.
Starting as soon as Monday, Aug. 31, the entrance ramp from Houghton Road to eastbound I-10 and the exit ramp from westbound I-10 to Houghton Road will close for nearly three months. The full closures of the two ramps will allow crews to reconstruct the ramps in one phase. Traffic will be detoured to the Colossal Cave/Wentworth Road interchange.
Starting in September, motorists can expect the following overnight restrictions at times:
Narrowing I-10 to a single lane in each direction
Occasional closures of Houghton Road at I-10
Occasional closures of various ramps between I-10 and Houghton Road
The project is scheduled for completion in late 2021.