Proposed diverging diamond interchange at Prince William Parkway and roundabout at Godwin Drive
On July 30, 2026, Prince William County’s Department of Transportation and Capital Construction held a public information meeting to present and discuss its preliminary proposal to construct a diverging diamond interchange (DDI) at Prince William Parkway and Clover Hill Road, to reduce travel delays along the Parkway and accommodate the planned introduction of scheduled commercial airline service at the newly renamed Washington Manassas Airport.
On August 12, 2026, Active Prince William Co-Chair Allen Muchnick submitted the following public comments to supplement the comments submitted previously by Co-Chair Mark Scheufler and by member Connor Young, both of whom are professional engineers. Connor’s detailed comments in the form of a PowerPoint presentation can be viewed here.
Re: Proposed Design for the Prince William Parkway and Clover Hill Road Interchange Project
I’m writing on behalf of Active Prince William to comment on the proposed design for the Prince William Parkway and Clover Hill Road Interchange Project as presented at the July 30, 2026 public information meeting. This letter supports and expands upon the comments previously submitted by Active Prince William members Mark Scheufler and Connor Young.
1. Examine More Cost-Effective Alternatives to a Diverging Diamond Interchange:
A diverging diamond interchange seems excessive for the anticipated future traffic volumes at this location, and we recommend that the project team evaluate an interchange design similar to that recently approved for the Prince William Parkway/Sudley Manor Drive Interchange which would serve both Sudley Manor Drive and Wellington Road traffic.
For 2025, the annual average daily traffic (AADT) volumes along these adjoining segments of Clover Hill Road (Rte 3235) was only 3200, far less than the traffic volumes on the two existing Prince William County highways with diverging diamond interchanges, both of which are high-speed, high-volume, median-divided arterial roadways. Route 15 at I-66 had a 2025 AADT of 38,000, whereas Balls Ford Road (Rte 621) at Prince William Parkway had an AADT of 20,000. Thus, Clover Hill Road would still carry far less traffic than either existing diverging diamond interchange did in 2025, even if Clover Hill Road traffic volumes were to double or triple with the future expansion of Washington Manassas Airport.
For the proposed Prince William Parkway/Sudley Manor Drive interchange, the existing at-grade intersections along Prince William Parkway at both Sudley Manor Drive and Wellington Road would be modified to allow only right-in and right-out traffic movements, and both Sudley Manor Drive and Wellington Road would cross over the Prince William Parkway on a single new roadway overpass on a new alignment.
In 2025, Sudley Manor Drive had an AADT of 26,000 on the east side of Prince William Parkway, while the adjoining segment of Wellington Road had an AADT of 18,000. If such an interchange design can handle two arterial roads with a combined AADT of 44,000, a similar interchange design should have ample capacity to accommodate Clover Hill Road well into the distant future.
The approved design for the Prince William Parkway Interchange at Sudley Manor Drive and Wellington Road
Thus, the design team should explore a Clover Hill Road-Prince William Parkway interchange design where Clover Hill Road’s existing at-grade intersections with the Parkway are modified to allow only right-in and right-out traffic movements, and a new Clover Hill Road overpass of the Parkway would be constructed on a different alignment.
Even if Clover Hill Road traffic volumes were to grow five- or six-fold in the future, this new Clover Hill Road bridge should function effectively with only one travel lane in each direction (and only a single shared-use path and no sidewalk along one side of the bridge should be adequate). The project savings due to the narrower and simpler bridge could be enormous. The bridge roadway could connect to the existing segments of Clover Hill Road with either roundabouts or signalized intersections.
Our alternative, lower-cost proposal for the Prince William Parkway and Clover Hill Road Interchange
It does not appear that such an interchange concept has been evaluated for this project. If indeed feasible, this alternative concept should cost considerably less to build and be much easier to fully fund.
2. Extend the Project Limits Northwest Along Godwin Drive in the City of Manassas to Reach Winged Elm Circle
Godwin Drive in the City of Manassas–between Clover Hill Road and the southeast leg of Winged Elm Circle–has only one narrow sidewalk, no shared-use paths, and no bicycle lanes. To provide continuous on-road bike lanes between the proposed roundabout and the southeast leg of Winged Elm Circle, the project limits should be extended northwest about 850 feet along Godwin Drive to Winged Elm Circle. Ideally, a second sidewalk or a shared-use path should also be constructed along this segment of Godwin Drive along its northbound side.
Godwin Drive between the proposed roundabout at Clover Hill Road and the southeast leg of Winged Elm Circle
Building this missing bike lane segment would finally provide a continuous bicycle facility along Godwin Drive between Hastings Drive and Clover Hill Road. As traffic volumes increase along Godwin Drive due to the future expansion of Washington Manassas Airport, the need for a continuous bicycle facility will grow considerably.
3. Install Shared-Lane Markings to Guide Bicycling Movements though the Clover Hill Road-Godwin Drive Roundabout.
Although the proposed design includes shared-use paths along the rebuilt segments of Clover Hill Road and along the roundabout, most people bicycling through the roundabout will be approaching and leaving the roundabout on the roadway and won’t necessarily access any shared-use path unless they are traveling to the airport along the rebuilt segment of Clover Hill Road.
Proposed roundabout at Clover Hill Road and Godwin Drive
Installing shared-lane bicycle markings (sharrows) within the roundabout would especially help guide bicycling movements between both legs of Godwin Drive and the leg of Clover Hill Road approaching the City of Manassas and also assist in calming traffic.
4. Design the Interchange to Effectively Accommodate the Planned Future Shared-Use Path along Prince William Parkway.
We appreciate that the design of this project would incorporate the right-of-way for a future shared-use path along the northbound side of the Prince William Parkway. Please ensure that the design of this project would a) accommodate that shared-use path without any motor-vehicle cross-flows and b) connect seamlessly to the new shared-use paths along Clover Hill Road that will be built as part of this Interchange project.
One way to accomplish this would be to incorporate box culverts in this project beneath all new parkway exit and entrance ramps on the northbound side of the Parkway, to provide a safe and efficient underpass route for the future shared-use path along the Parkway. Doing so would also reduce the cost and disruption needed when the long-planned shared-use path along this segment of the Parkway is finally built.
5. Appropriately Design Clover Hill Road on the East Side of the Parkway and the Roundabout at Godwin Drive for Slow Vehicular Speeds through Residential Neighborhoods.
While the proposed lane widths and vehicular capacity for Clover Hill Road and the DDI Bridge seem excessive and would unnecessarily inflate project costs and degrade highway safety, it is especially important that Clover Hill Road on the east side of the Parkway and the Godwin Drive Roundabout be designed for slow (under 25 MPH) travel speeds appropriate for residential neighborhoods. In that regard, the travel lanes and circulatory lanes in the roundabout should be 10 feet (or at most 11 feet) wide, especially since a wide truck apron in the roundabout would adequately accommodate all oversized vehicles and since the roundabout would include a dedicated right-turn-only lane for traffic heading southeast on Godwin Drive.
In addition, residential traffic-calming measures, such as speed humps along northbound Clover Hill Road and speed tables at the crosswalks within the roundabout should be considered.
Thank you for giving the public this opportunity to comment at an early stage of project design. We very much appreciate the commitment of the project team to integrate pedestrian and bicycling infrastructure and safe roadway crossings into the design of this project.
