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Project Information

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County:Calvert Project Number:SM351_11
Project Name:
MD 4, Patuxent Beach Road and Solomons Island Road

Location of Project:

Study to upgrade MD 4 between MD 2 and MD 235 (4.0 miles), including the Governor Thomas Johnson Memorial Bridge (Bridge 04019) over the Patuxent River and the intersection at MD 235 (2.9 miles).
Project Area Map

The project limits of the MD 4 Thomas Johnson Bridge Planning Study area extend approximately 4.1 miles, from the intersection of MD 2 / MD 4 with Patuxent Point Parkway in southern Calvert County, across the Thomas Johnson Bridge, to the MD 4 / MD 235 intersection in St. Mary's County. The purpose of the project is to improve existing capacity and traffic operations, improve vehicular, pedestrian and bicycle safety along the MD 4 study corridor, while simultaneously supporting existing and planned development.

MD 4 provides area commuters with access to the District of Columbia (Washington, DC), and the Patuxent Naval Air Station, St. Mary's largest employer. The Thomas Johnson Bridge, built in 1977, is a two-lane bridge that connects St. Mary's and Calvert counties over the Patuxent River and serves as an evacuation route for the Calvert Cliffs Nuclear Power Station. High traffic volumes across the bridge during peak travel periods cause frequent traffic delays. During bridge maintenance activities or following crashes, traffic frequently comes to a stop, as bridge shoulder widths are insufficient to handle emergency and repair vehicles. Additional information on existing and projected traffic demand, environmental, economic, demographic land use characteristics can be found in the MD 4 Thomas Johnson Bridge Project Planning Study, May 2008: Purpose and Need Document.

What Is Under Study:
The Maryland Department of Transportation State Highway Administration (MDOT SHA), secured Federal Highway Administration (FHWA) Location Approval of SHA’s “Preferred Alternative” on September 10, 2015, concluding the Project Planning Phase of this Project. The Preferred Alternative, as described in the 2015 Finding of No Significant Impact” (FONSI), MD 4 - Thomas Johnson Bridge Project Planning Study, includes improvements along four separate segments of the study area. Upon receipt of FHWA approval of the FONSI, the Preferred Alternative is referred to as the Selected Alternative.

Description of Proposed Improvements
  1. MD 235/MD 4 Single Point Urban Interchange (SPUI)
  2. Rendering of SPUI
    • MD 235 would be elevated over MD 4, with two through lanes in each direction.
    • MD 4 would remain at-grade with two through lanes in each direction, turn lanes and a traffic signal located under the MD 235 bridge and include a bicyclists / pedestrian path.
    • Ramps along MD 235 would direct all left-turning vehicles to the MD 4 signalized intersection.
    • Properties located on northbound MD 235 would gain access to MD 235 through two new service roads.
  3. MD 4 Mainline, St. Mary’s County: Four-Lane Roadway with Open Median
    • Typical Section-MD 4 Mainline, St. Mary's County
    • MD 4 would be widened to four lanes and include a median.
    • The existing road would be reconstructed to carry northbound traffic and include a bicyclists / pedestrian path.
    • Two new lanes, constructed to the north of the existing road, would carry southbound traffic.
  4. Thomas Johnson Bridge- New Four-Lane Parallel Span
    • Typical Section - Thomas Johnson Bridge
    • A new bridge would be built to the south of the existing bridge and would include a bicyclists / pedestrian path.
    • Outside shoulders would accommodate emergency and disabled vehicles.
  5. MD 4 Mainline Calvert County - Four-Lane Roadway with Open Median

    • MD 4 would be widened from north of the Patuxent River crossing to the MD 4/Patuxent Point Parkway intersection.
    • A new right-in/right-out access point for MD 4 northbound / Solomons Island Road would be provided north of the closed access.
Click on the Documents tab for additional planning study details. Selected Alternative Maps may be viewed on the Maps tab .MD 4 Corridor Study Update Open House - May 23, 2018: 5:30 - 7:30 pm
    Esperanza Middle School
    22790 Maple Road
    Lexington Park, MD 20653

Status of the study will be presented in a series of maps and exhibits. You may arrive at any time during the workshop hours. There will be no formal presentation.

Detailed Project Information:

Project Type:

Current Phase:Planning
Funded Year :2007 How much will this project cost?
Funding Source(s):State/Federal
Last Updated On : 5/11/2018


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