CALVERT COUNTY, Md. — The Maryland Department of Transportation State Highway Administration will inspect the MD 4 bridge over the Patuxent River, known as the Governor Thomas Johnson Bridge, at the Calvert and St. Mary’s county line starting Sunday night, November 9, 2025. Crews will work overnight through Thursday, November 13, from 9 p.m. to 5 a.m. each night, weather permitting, closing one lane and directing alternating traffic through the open lane with flagging operations.
The inspections, performed by contractor Hardesty & Hanover of Annapolis, will evaluate key structural components to maintain safety and compliance with federal standards. Teams use specialized equipment, including under-bridge access platforms and nondestructive testing tools, to examine the deck surface for cracks, railings for stability and substructures for corrosion or wear. These checks follow National Bridge Inspection Standards, requiring hands-on assessments within arm’s reach for critical elements like fracture-prone members, conducted more frequently than the typical two-year cycle for this high-traffic span. Portable variable message signs will alert drivers along MD 4, MD 2 and MD 235 in advance.
Commuters crossing between Lusby in Calvert County and Solomons in St. Mary’s should anticipate delays of 10 to 20 minutes per crossing during the overnight windows, based on similar past operations that handled up to 500 vehicles per hour under single-lane control. The bridge carries about 25,000 vehicles daily, with evening peaks from shift workers at Naval Air Station Patuxent River heading north to Anne Arundel County. Flaggers, equipped with handheld stop-go paddles and LED vests, will manage flow to prevent backups extending south to the MD 2 interchange or north toward Prince Frederick.
Maryland requires such evaluations to identify issues early, preventing closures like those seen on other Patuxent spans during repairs. Recent data from MDOT SHA shows the bridge maintains a fair condition rating, with no major deficiencies noted in the latest biennial report, but routine scans ensure load capacities hold under increasing freight volumes from regional ports. Crews will document findings via digital mapping software, prioritizing any immediate fixes such as joint sealing or guardrail reinforcements.
Drivers are urged to reduce speeds in the zone, where limits drop to 25 mph, and watch for workers and equipment near the edges. Distracted or speeding vehicles account for nearly half of work-zone incidents statewide, per MDOT statistics, so staying focused helps protect crews climbing access points 100 feet above the water. For breakdowns, dial #77 on cell phones for free state police assistance, available around the clock.
Alternative routes include US 301 north through La Plata in Charles County, adding 25 miles but avoiding the river crossing, or the Thomas J. Hatem Memorial Bridge east on I-95 with a toll, suitable for those bound for Baltimore. Southern Maryland Regional Transit buses on routes like 201 from Leonardtown to Annapolis operate daytime only, so overnight travelers may need rideshares. Real-time updates appear on the MDOT 511 app or website, tracking incidents that could compound delays, such as fog common on the Patuxent in November.
The District 5 office, covering Southern Maryland highways, coordinates these efforts with local fire and police in Prince Frederick and Leonardtown to handle emergencies without halting inspections. Contact them at 410-841-1000 or toll-free 1-800-331-5603 for questions. Full details are on the MDOT SHA site.
In Calvert and St. Mary’s, where the bridge links residential areas to job centers, these overnight slots minimize daytime disruptions for school buses and delivery trucks. Past inspections, like one in March 2025, confirmed no structural concerns after four nights of similar lane restrictions, allowing quick resumption of full capacity. Officials note that while flagging adds wait times, it ensures thorough coverage without full shutdowns, a method refined through MDOT training programs for crews.
Safety extends to pedestrians and boaters below; inspections pause if vessels approach the 140-foot clearance, per Coast Guard protocols. Drivers hauling hazmat loads, common on MD 4 for Pax River support, receive escorts if needed. The work aligns with MDOT’s $200 million annual bridge investment statewide, focusing on preventive measures to sustain the span’s role in daily commutes.