Wilmot Road Case Study

After Four Month Hiatus, Temporary Acrow Bridge Once Again Put in Service During New Construction on I-10 in Tucson

Safe and cost-effective solution minimizes work zone impact

As the major east-west Interstate highway across Arizona, Interstate 10 is heavily traveled by both commercial and private vehicles. Built in the 1950s and 1960s, the highway is prone to frequent improvement projects. When it was determined the bridge decks over Wilmot Road in Tucson needed replacing and a temporary bridge would be needed, the Arizona Department of Transportation (ADOT) chose a detour bridging solution from Acrow. It was the second time the same Acrow bridge was used for similar projects on I-10 in a little more than a year.

In early 2017, ADOT selected and installed the modular Acrow bridge as a detour during the renovation and replacement of the bridge decks over Craycroft Road in Tucson. Owing to the success of that project, upon its completion in October 2017, the rental structure was stored until needed for a project with the same scope at Wilmot Road, a little more than a mile away.

For the Wilmot Road project, the 200-ton, 200-feet-long Acrow modular bridge was installed in late April and opened to traffic in May. The detour bridge was constructed on-site and assembled in the median space between the existing bridges. It was configured to carry eastbound traffic during deck renovation on the eastbound route. Upon completion of that phase of the project, anticipated to be in August, the process will be reversed, with westbound traffic moving to Acrow’s temporary structure and eastbound traffic returning to its original lanes. The entire project is expected to be completed in December, at which point the Acrow structure will be removed.

In recent years, state DOTs have increasingly selected detours over other re-routing methods during construction. In addition to ensuring a safer site for workers and the traveling public, bypass bridging can help minimize traffic delay costs, which are of particular concern with projects on busy Interstate highways.

“Using a temporary bridge allows us to extend the life of this bridge while causing the least possible delay for Pima County drivers,” said Rod Lane, district engineer for ADOT’s South Central District.

Added Bill Killeen, CEO of Acrow Bridge, “Acrow’s modular bridges, available for rent or purchase, are a great choice for detours when state DOTs and contractors need to stay on or ahead of schedule and, at the same time, assure motorist and worker safety.”

Wilmot Road Case Study Bridge Length
  • 200 feet
Bridge Width
  • 30 feet
Live Load
  • HL-93
Deck Surface
  • Epoxy
Bridge Finish
  • All major components galvanized to AASHTO M111 – ASTM A 123
  • All bolts are hot dipped galvanized
  • All pins are electro galvanized
Bridge Erection
  • Crane Assisted
Bridge Design
  • (A) Panel chords, diagonals, verticals, panel reinforcing chords, rakers to AASHTO M223 GD 65
  • (B) Raker brace, transom, top chord brace, swaybrace, transom brace, diagonal chord brace to AASHTO GD 50
  • (C) Panel pins to ASTM A 193 GD b7
  • (D) Bolts to AASHTO M164M – A325