Route 7 Corridor Improvements Utility Engineering

Fairfax County, Virginia

This high profile project is located on Route 7 (Leesburg Pike), one of the most congested thoroughfares in Northern Virginia, just west of the Route 7 / Dulles Toll Road interchange in Fairfax County. The project included widening of about a 6.8 mile segment of Route 7 from four to six lanes between Jarrett Valley Drive and Reston Avenue. The purpose of the project is to increase capacity, improve traffic operations and reduce congestion, improve access management, and improve safety in corridor.

The Virginia Department of Transportation (VDOT) awarded this project to a design-build team. SAM’s scope of services was to provide the depictions of utilities at the appropriate Quality Level (B, C or D) onto the design plans in the preliminary engineering phase. As the design progressed, “Quality Level A” utility data at specific locations was required to resolve conflicts between the roadway design and existing utilities. SAM, LLC performed utility records research, designating, locating, survey, quality assurance, professional review, and mapping in accordance with ASCE Standard CI/ASCE 38-02, Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data, the subsurface utility engineering profession (SUE), and pertinent FHWA and AASHTO documents.

The majority of the work was along the highly traveled and congested sections of the four lane secondary road. SAM performed Quality Level “B” mapping of 464,032 linear feet of underground utilities at Quality Level B and another 17,678 linear feet at Quality Levels C & D.
SAM excavated and documented “Quality Level A” information at 498 test hole locations. The test holes were produced using non-destructive “air-vacuum” excavation, surveyed to applicable tolerances, backfilled in compacted 6″ lifts and patched to VDOT specifications. The test holes documented the precise horizontal and vertical location of the utilities at points of potential conflict with the design.

Concurrent with the Route 7 Corridor Improvements project, the design-build team also coordinated with Washington Gas for the 24″ transmission line upgrade project occurring in the same project footprint during the same timeline.

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