HDR - Southwest Parkway flythrough

In January 2006, NTTA selected architectural, engineering and consulting company HDR to design a new, five-level interchange at state highways 183 and 121, and Interstate 20. The project has an estimated construction cost of US$ 314 million and represents the largest of five segments comprising the Parkway. HDR’s segment involved design of 2 miles (3.2 km) of six new lanes on the Southwest Parkway with localized frontage roads, more than one mile of reconstruction for SH 183 with new frontage roads, and direct connectors to the I-20. The bridge design for this fully-directional interchange included the design of numerous overpass bridges, reconstruction of one cross-street underpass and nine direct connector bridges (several thousand feet-long ramp structures to provide uninterrupted access between freeways).