S. George Mason Dr. & S. Four Mile Run Dr. Intersection Study

Project Introduction Video Now Available

Join our project manager and learn more about this study and what we're working on for this key intersection with our short video update:

Learn More!

Status

Planning

The study is underway and the project team has released a short video with the history of this project, the challenges posed by this intersection, and what our next steps are for people who walk, bike, ride transit and drive through this key intersection in Southern Arlington.

Location

This study will advance the two preliminary design concepts for the intersection of S. Four Mile Run Drive, S. George Mason Drive, and the Washington & Old Dominion Trail. It includes the fundamental analysis for both options and includes additional review of what is necessary to grade-separate the W&OD trail from the intersection.

About the Project

The feasibility analysis launched in partnership with the Metropolitan Washington Council of Governments (MWCOG) Regional Roadway Safety in Winter 2024/5.

The project team will explore the feasibility of the intersection treatments proposed in the South George Mason Drive Multimodal Transportation Study: improvements made to a conventional intersection, a peanutabout, and a grade separated W&OD trail.

A peanutabout incorporates design features and operations of a typical roundabout. They are often used to help manage vehicle speeds and reduce the number of conflict points between motorists, trail users, bicyclists and pedestrians.

The feasibility study will focus on evaluating alternatives based on improvements to traffic operations and the safety of people walking, biking, taking transit, and driving.

Project Goals

Document existing conditions
Determine the feasibility of a peanutabout style intersection
Determine the feasibility of a grade separated W&OD trail
Identify preferred intersection concept using results of existing conditions, safety and traffic operations analyses

Project Background

The intersection of South George Mason Drive, S. Four Mile Run and W&OD trail is an identified Vision Zero Hotspot.
- The intersection was studied by Vision Zero as part of the Four Mile Run Drive Road Safety Audit (2022) and the South George Mason Drive Safety Audit (2023).
The South George Mason Drive Multimodal Transportation Study (2023) developed preliminary plans to improve safety and access for people cycling, riding transit, walking/rolling and driving.
- This intersection received the highest number of public comments along the South George Mason Drive Corridor.
  - Many people found the intersection to be complex, inconvenient, and confusing and asked for changes to improve the safety for all users.
- The public indicated an interest in pursuing a unique treatment, a peanutabout, as a possible solution to the complex intersection of S. Four Mile Run, S. George Mason Drive, and the W&OD trail.

Public Process

Summer 2025 - Project Introduction Video

Join project manager Brian Shelton as he introduces the study and walks you through what we are looking at for this challenging intersection, how we're using the recommendations from the South George Mason Drive Multimodal Transportation Study, and what our next steps will be at the end of the study process.

English | Spanish

This video covers what we're studying through this project, including:

An improved signalized intersection
A peanutabout
- A peanutabout incorporates design features and operations of a typical roundabout. They are often used to help manage vehicle speeds and reduce the number of conflict points between motorists, trail users, bicyclists and pedestrians.
A grade separated W&OD trail

Following the study, the project team will host a public engagement opportunity to add your feedback to what we've learned about these possibilities, and identify next steps for the intersection as we move forward.

Fall 2025 - Study Results & Preferred Concept

Anticipated Fall 2025, and will include a public engagement opportunity and public review of the findings from the study for each of the concept design alternatives.

Funding

This feasibility study is funded by a competitive grant awarded to the county from the Metropolitan Washington Council of Governments Regional Roadway Safety Program.