I-10: Houghton Road DDI Interchange

Ames Construction reconfigured the interchange at Houghton Road and I-10 in Tucson, Arizona, building the city’s first diverging diamond interchange (DDI) and the second DDI in the state.

The 16-month project included the construction of a new, wider Houghton Road Bridge over I-10 just west of the existing bridge, widening Houghton Road to three lanes in each direction through the interchange, realigning Rocket Road on the north side of the interchange, and improving accessibility for bicyclists and pedestrians. Project scope included 15 drilled shaft foundations, storm drainage, retaining walls, and box culvert extensions.

Designed to handle heavier traffic while being safer for drivers, the DDI moves traffic over the bridge while briefly switching to the opposite side of the road to facilitate traffic flow. The reconstructed interchange increases the daily capacity of traffic from 8,000 to 50,000, providing relief for motorists accessing existing and planned residential and business developments in the growing region.

Learn more:
Arizona Department of Transportation (ADOT)