Rinker Design Associates (RDA) provided professional engineering services for the design of Stringfellow Road (Route 645) from Fair Lakes Boulevard (Route 7735) to Lee Jackson Memorial Highway (Route 50). This design work included the intersection of Stringfellow Road at Route 50 and the associated approaches. The roadway design was administered by VDOT but was designed per Fairfax County’s direction.

The project consisted of widening the existing two-lane roadway to a four-lane divided roadway with sidewalks, trails, curb, gutter, and a raised median for the length of 2.02 miles from Route 7735 to Route 50. RDA provided complete right-of-way and construction plans including roadway design, hydrologic and hydraulic analysis, traffic engineering analysis and design, and traffic data collection. RDA also designed signage plans, pavement marking plans, signalization, lighting plans, ITS, retaining walls and permit sketches.

The project passes through a densely populated residential corridor with public facilities including a library, two schools, two parks, as well as several stream crossings. One of the main design elements was the major stream crossing of Little Rocky Run; another was the simultaneous coordination of several major utilities, including a newly installed 24” water main, several large bore aviation fuel pipelines (6”–36” in diameter) that serve Dulles Airport’s fuel farm, and numerous other overhead and underground lines. RDA’s extensive coordination with various utility companies on this project facilitated the removal or relocation of each line and resulted in a savings of more than $4 million in construction costs, as well as more than a year of advancement to the project schedule.

• Design Roadway to widen Rt. 645 from two (2) lanes to four (4) lanes
• Hydrologic and Hydraulic Analysis
• Design major Con-Span culvert on Little Rocky Run
• Coordination for extensive Utility relocations
• Retaining wall design
• Traffic engineering analysis
• Traffic data collection
• Design for Signage and pavement marking plans
• Signalization design
• Lighting plans and ITS
• Supplemental survey data with roadway design
• Construction coordination and support