Route 7 Corridor Study between Route 28 and the Fairfax County Line
Route 7 Corridor Study – Route 28 to Fairfax County Line
Welcome to Loudoun County’s Department of Transportation and Capital Infrastructure’s (DTCI) public input meeting site.
This draft corridor study examined existing and projected future conditions along Route 7 in Loudoun County, Virginia, between the Route 28 interchange and Dranesville Road (Route 228) at the Fairfax County line, approximately 4.25 miles.
A corridor study is a planning project that defines the relationships between a roadway and its adjacent land. Corridor studies are used to:
- Define acceptable levels of access and mobility,
- Determine transportation system needs to support surrounding land uses,
- Consolidate and control access points,
- Identify operational deficiencies and promote operational efficiency, and
- Promote redevelopment of an underperforming corridor.
Corridor studies evaluate conditions for a projected design horizon, usually approximately 20 years into the future. For this study, the Design Year of 2040 was selected as this study was initiated in 2020. The public meeting will examine the safety and traffic operations for Existing Year 2020, plus travel forecasting and traffic operations for the Design Year 2040 No-Build and Build alternatives. The study team is seeking the public’s input on the interim safety improvements and the alternatives and areas needing attention along this corridor.
The intent of each proposed alternative for the Route 7 corridor is to produce a multimodal transportation facility that fits its physical setting and preserves scenic, aesthetic, historic and environmental resources, while maintaining safety and mobility. The approach to developing this type of corridor is known as a Context-Sensitive Solution, which considers the total environment within which a transportation improvement project will exist. It is an approach to planning and designing transportation projects that balances the competing interest of diverse stakeholders and allows flexibility in design to maintain the safety of all users regardless of the travel mode they choose.
According to the 2019 Loudoun County Countywide Transportation Plan (CTP), 6-foot-wide sidewalks, 10-foot-wide shared use paths, and on-road bicycle lanes (or a combination thereof) are required on arterial and collector roadways. All improvements proposed in this corridor study, including the proposed alternatives below, adhere to the 2019 CTP.
View the information below for details about the proposed alternatives. To advance the slides, click on the arrow at the right of the slide deck.
Alternative 1: Superstreet
The first alternative was developed based in part on the results of this initial vJuST screening, and considered the projected capacity needs, estimated costs, and right of way limitations. This alternative consists of several Restricted Center U-Turn (RCUT) intersections. For more information about RCUT intersections, including a graphic depicting how existing turning movements are rerouted, view VDOT's Innovative Intersections and Interchanges page.
The primary purpose of Alternative 1- Superstreet configuration (graphic below) is to reduce delay and improve peak direction travel times for through traffic along Route 7, while improving safety through the reduction of the number of conflict points at the signalized cross-street intersections. Alternative 1 adds four new traffic signals along Route 7 where it was feasible based on the spacing between the existing signalized intersections, resulting in a total of 12 signalized intersections within the study corridor. Most of the signalized intersections will be simplified to fewer signal phases at each intersection, as shown below. Click on the image to view and enlarge the PDF.
While this alternative was able to make significant operational improvements along the corridor with minimal right-of-way impacts, this solution would not solve all of corridor’s operational issues.
Alternative 2: Removal of Traffic Signals
Removal of Traffic Signals (graphic below) removes traffic signals along the Route 7 study corridor. The existing interchanges remain untouched at is as Route 28 and Atlantic Boulevard/Algonkian Parkway. The interchange at Cascades is converted to a half cloverleaf to the west. Most traffic signals would be removed along the corridor. Click on the image to view and enlarge the PDF.
The study team did not advance this option beyond the initial screening due to the anticipated significant right-of-way impacts expected along the corridor.
Alternative 3: Service Roads
Service Roads (graphic below) uses service roads to connect properties and roadways to Route 7; meaning that access to properties would be on roads other than Route 7. In addition, the existing interchanges would be modified and turning movements along the Route 7 corridor would be limited. Click the image to view and enlarge the PDF.
The study team did not advance this option beyond the initial screening due to the anticipated significant right-of-way and business access impacts expected along the corridor.
Alternative 4: Hybrid Arterial
Hybrid Arterial (graphic below) balances the capacity needs for local and commuter traffic along Route 7. A combination of grade separations west of Cascades Parkway, at-grade intersection improvements, “Green T” intersections and selected grade separated movements, east of Cascades Parkway including a “Center Turn Overpass” at Potomac View Road would be employed to convey traffic. For more information about Green T intersection, including graphics, view VDOT's Innovative Intersections and Interchanges page.
The intent would be to facilitate flow of the most critical movements along the Route 7 corridor. For example, since there is a high volume of traffic between Potomac View Road and Route 7 to the east in Fairfax County, a series of median overpasses combined with “Green T intersections” will facilitate this traffic flow. Similarly, to the west of Cascades Parkway, there is a significant amount of traffic turning to the cross streets; by separating these movements from the main line traffic and placing them on service roads, the overall flow of traffic is greatly improved. Alternative 4 also has the benefit of being able to be constructed in multiple phases, allowing smaller segments to be built over time as funding is available. Click the image to view and enlarge the PDF.
The analysis of this alternative shows that the performance improvements realized from the proposed configuration significantly enhances traffic flow through the corridor while providing for the needed access to the adjacent properties.
No Build Alternative
The term No Build is essentially what it says - the study team evaluates the conditions expected along the corridor to determine what conditions will be if no improvements, other than Comprehensive Transportation Plan (CTP) projects, are made to the corridor. The existing and future No-Build conditions along Route 7 consist of conventional signalized and unsignalized at-grade intersections, as well as ramp merge, diverge, and weave sections at interchanges. The No-Build option is typically evaluated alongside one or more “Build” options to evaluate the proposed Build options relative to not making any improvements to the corridor.
Based on observations as well as the traffic operations analysis results presented in this study for the existing and future No-Build conditions, there are safety and performance deficiencies along this corridor that may require unconventional solutions. Therefore, an early step in the concept development process was to use the Virginia Department of Transportation (VDOT) Junction Screening Tool (vJuST) to help identify innovative intersection and interchange configurations that might be appropriate and feasible along the Route 7 corridor.
Potential Interim Safety Improvements
In addition to addressing the long-term improvement plan, the study also focused on prioritizing some safety improvements along the corridor as interim measures until the full complement of improvements is implemented. Each of these interim measures could be constructed individually to provide improvements to the traffic flow; however, combinations may be desirable to optimize traffic flow along the corridor.
Potomac View Road
Westbound approach: extend left turn storage length and angle away from adjacent thru lanes.
Safety issue addressed: Westbound sideswipe crashes; vehicles may be trying to squeeze past queued thru vehicles to access the left-turn lanes.
North Sterling Boulevard
- Green-Tee Intersection for Sterling Boulevard with Right In/Right Out-only for Cardinal Glen Circle.
Safety issue addressed: Reduces number of conflict points at the intersection; makes westbound free-flow to reduce westbound rear-end crashes.
- Change northbound approach to Left, Left, Through, Right turning movements and southbound approach to Left, shared Through-Right turning movements; replace North/South split-phasing with concurrent protected-only northbound and southbound left-turn phasing.
Safety issue addressed: Simplifies the northbound approach by eliminating the existing triple-left turn lanes and the confusing shared left/thru/right-turn lane, thus improving northbound traffic flow and potentially reducing rear-end and side-swipe collisions.
- Replace painted northbound right turn channelizing island with a raised concrete island.
Safety issue addressed: Simplifies the northbound right-turn movement which may improve northbound traffic flow and reduce rear-end and sideswipe crashes.
- Green-T Intersection.
Safety issue addressed: Reduces number of conflict points at the intersection; makes eastbound free-flow to reduce eastbound rear-end crashes.
- Southbound approach No Turn on Red.
Safety issue addressed: May reduce likelihood of angle crashes due to apparent insufficient sight distance looking left from the SB approach
- On the southbound approach, move the right turn lane stop line closer to the intersection and allow Right Turn on Red.
Safety issue addressed: Improves sight distance looking left from the southbound approach for right turns and reduces the likelihood of angle crashes.
Close the median crossover and make southbound approach Right In/Right Out-only.
Safety issue addressed: Reduces number of conflict points at this unsignalized intersection.
Lakeland Drive and Community Plaza
Convert to Restricted Center U-Turn intersection (Northbound and southbound approaches are right-turn only, with U-turns downstream eastbound at Dranesville Road and westbound at Augusta Drive (close Cedar Drive median crossover for this option).
Safety issue addressed: Reduces number of conflict points.
- Alternative 4 Road Graphics Revised (PDF)
- Route 7 Corridor Study Final Report (PDF)
- Public Information Meeting - July 13, 2021
- October 19, 2021 Board of Supervisors Meeting
- Route 7 Concept Study – Traffic Operations and Safety Report February 2021 (PDF)
- 2017 Transportation Summit Presentation (PDF)
- June 29, 2017 Transportation Summit Board of Supervisors' Information Item (PDF)