Specifications include, but are not limited to: Provide the Environmental Engineering Services for DNT Extension from US 380 to FM 428. The Dallas North Tollway (DNT) is an access-controlled toll facility that stretches from Interstate Highway (IH) 35E in Dallas to U.S. Highway (US) 380 in Frisco, a distance of approximately 32 miles. The DNT was completed in segments by the North Texas Tollway Authority (Authority). The existing DNT is a six- to eight-lane facility (three to four mainlanes in each direction) with a variable width median. The Dallas Parkway runs parallel to the DNT mainlanes and consists of variable-width frontage roads in both north and south directions from IH 635 to US 380. The Dallas Parkway continues from US 380 and Farm-to-Market Road (FM) 428 with two lanes in both north and south directions on either side of an open median. The Authority has identified the need to extend the DNT mainlanes northward from its existing northern terminus at US 380 to FM 428. The work to be performed by the Engineer under this contract consists of providing preliminary engineering services including updating the existing schematic design, reevaluating previously approved environmental studies, and conducting associated public involvement in support of the schematic and environmental studies for: Extending the Dallas North Tollway by four mainlanes in each direction within existing right-ofway (ROW) from north of US 380 to FM 428.
