Spring Hill and Lewinsville Roads Intersection Improvement Study
Spring Hill Road serves as a north-south connection to the Dulles Toll Road for the residential communities of McLean and Great Falls to the north and west of Tysons. The first signalized intersection with Spring Hill Road is with Lewinsville Road, located approximately one quarter of a mile north of the Dulles Toll Road. Lewinsville Road runs east-west to the north of the Dulles Toll Road and connects Leesburg Pike (Route 7) with Dolley Madison Boulevard (Route 123). Figure 1 provides an overview of the study area and location relative to the surrounding areas of Tysons and McLean.
As part of the Tysons Neighborhood Study, FCDOT identified the need to improve the Spring Hill Road and Lewinsville Road signalized intersection. The intersection has a severely skewed intersection angle, and experiences peak hour congestion, significant cut-through traffic, long queues, and has a documented crash history. The proximity to Spring Hill Elementary School is another contributing factor to the recurring congestion and significant queue spillbacks from the intersection. A previous study of this intersection, also part of the Tysons Neighborhood Study, looked at enhancements to the existing signalized intersection operations as well as several roundabout configurations.
FCDOT initiated the current study to perform preliminary engineering and conceptual design. The study initially developed and evaluated four preliminary concepts (presented May 2018) to improve intersection traffic operations and safety for all modes. The concepts were done at a planning level of analysis and show conceptual geometric layouts and roadway characteristics that convey potential right-of-way needs, anticipated utility impacts (based on available information), and bicycle/pedestrian connections.
The preferred initial concept, the Conventional Intersection, was chosen based on community feedback from the four preliminary concepts. Considering a comprehensive evaluation process of the project measures-of-effectiveness and community feedback, a fifth intersection alternative, the Offset T-Intersection, was developed. Both the Offset T-Intersection and the Conventional Intersection alternatives were presented June 2019. The two preferred alternative concept drawings were later refined.
The final recommended alternative, the Offset T-Intersection, was selected based on a scoring system of the written feedback from the meeting and through an online survey available throughout the month. Between the two preferred concepts, the Offset T-Intersection received the highest average score, with the Conventional Intersection and No-Build alternatives placing second and third, respectively.