DART Orange Line LRT 1 & 2 Design-Build Project in Dallas County, Texas

IEA performed several tasks for this approximately $450 Million DART Orange line Design/Build project. The project limit was from Spur 482 in Dallas to DFW Airport, Irving.

Cost Savings: IEA developed value-added Alternative Technical Concepts (ATCs) that resulted in cost savings of $10M. The schematic alignment of the Orange Line crossed over three properties at the southwest corner of the Orange Line and Northwest Highway when the new line diverged from the Green Line to the west along the Northwest highway. The original alignment would have also required the modification of the signalized intersection of the Northwest Highway frontage road with Harry Hines along with utility relocations. IEA’s approach helped saved DART property acquisitions, property and utility relocations, and approximately 100’ of rail line. During the final design process, IEA designed transitions between the existing and proposed pavements, grading of the intersections to account for drainage, and vehicle traffic and pedestrian crosswalks. Incorporating the proposed design for the rail, IEA analysed the existing pavement to minimize the extended removal of concrete.

Street Intersections: IEA provided street intersection improvements at the intersections impacted by the DART Orange Line project. IEA’s responsibilities included roadway design, right-of-way (ROW) mapping, demolition (DEMO) plans, and utility coordination services for this one-mile roadway and nine-mile utility project. This task included several street and driveways intersections including Lake Carolyn Parkway/Las Colinas Boulevard, Lake Carolyn Parkway/California Crossing and Lake Carolyn Parkway/O’Conner Boulevard.

The ROW plans showed existing and proposed ROW and easements along the entire corridor. ROW and easements were developed to accommodate the proposed track alignment, parking facilities, retaining walls and slopes, and other rail related features and structures. The development of the plans involved coordination with various disciplines such as track designers, site developers, wall, drainage and other disciplines. DEMO plans accounted for removal of existing infrastructure to make way for the proposed track and associated features within the proposed ROW and easements. Removal items included existing walls, abandoned structures, roadway lighting features, signs and various other features. Development of DEMO plans also involved coordination with track designers, site developers and other disciplines.

Utilities: A total of 18 locations were analyzed for conflicts with the proposed light rail train construction with the existing gas / petroleum systems. The design team relocated approximately 1300 linear feet of conflicted Atmos gas pipe lines in 9 locations. The line sizes ranged from 2-inch to 6-inch. A total of 65 existing telecommunication systems locations were analysed for conflicts with the proposed light rail train construction. The design team replaced approximately 7500 linear feet of conflicted Telecommunication lines in 25 locations.

A total of 24 water system locations were analysed for conflicts with the proposed light rail train construction. In addition to the relocation work, the design team also designed the new fire safety needs (wet and dry fire suppression systems) due the construction of power sub-stations, instrument houses, and stations. The design team replaced approximately 1300 linear feet of conflicted water lines in 12 locations.

The wastewater system for the project was owned by three entities - City of Dallas, City of Irving, and DCURD. A detailed design was completed to each entity’s specific criteria and CADD standards.  A total of 18 locations were analysed for conflicts with the proposed light rail train construction. The design team replaced approximately 1950 linear feet of 12" wastewater and 1200 linear feet of 24" conflicted wastewater lines in two locations.