was transferred to the new structures the old lanes could simply be closed off and removed. Little of the original interchange remained when the project was finished. To save time and money, innovative construction methods were employed: The original plans called for the segments of the long ramps and spans (used to direct-connect roads) to be made of steel, but because building with steel would interfere with heavy traffic flow during construction, cast-in-place segmental concrete was substituted in the plans. However, Zachry decided to use precast concrete segmental bridges, rather than casting the bridge elements in place, and used a unique machine, designed and constructed by Deal S.R.L. of Italy and costing about $1 million, to move the pieces into place. During the construction, 2.2 million cubic yards of earthwork was used, 350,000 cubic yards of concrete was mixed on site, and 300,000 square feet of retaining walls were built. Additionally, 40,000 feet of drilled shafts and 75,000 linear feet of drainage pipe were completed. In addition to the construction of 43 permanent bridges, six temporary bridges were built, resulting in 2.3 million square feet of bridge deck. The project was designed by the HNTB Corporation, who provided professional engineering consultation throughout the construction, which had begun in 2002 and was completed in December 2005, more than 13 months sooner than planned. Recognition In 2006, the American Public Works Association named the High Five "Public Works Project of the Year" for its massive size, its innovative design, the complexity and rapidity of its construction, and the need it fulfilled for the community. TxDOT as the managing agency, Zachry Construction Corporation as the primary contractor, and HNTB Corporation as the primary consultant received the award in recognition of their cooperative alliance in completing the project. The interchange is ranked by Popular Mechanics as one of "The World's 18 Strangest Roadways", which called it a "labyrinth of lanes" and a "five-level marvel of engineering" because of its height, the number of its bridges and other unusual design and construction features. See also References External links Google Maps Satellite View Texas Freeway, includes picture of the old interchange Alternate view of old interchange Another view of the old interchange Dallas High Five Construction Photos, Feb.-May 2004 Dallas High Five Interchange Tour Dallas, TX, ScrewdUPClickV2 State highways in Texas Highways in Dallas Road interchanges in the United States U.S. Route 75