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Bridge conditions in St. Mary's County, Maryland

50 inventoried bridges · 2 rated poor · 2025 National Bridge Inventory

United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled August 20, 2026

St. Mary's County tracks close to typical: 2 of its 50 inventoried bridges (4.0%) are rated poor, against a national rate of about 7%.

2 of the 50 bridges in St. Mary's County, Maryland, are rated in poor condition (4.0%) in the 2025 National Bridge Inventory, as of August 20, 2026.
13 bridges (26.0%) are rated good and 35 (70.0%) fair.
The median St. Mary's County bridge was built in 1960.
The busiest poor-rated bridge is Md 5 over Hilton Run (built 1936), carrying about 8,010 vehicles a day.

Good 26.0% · Fair 70.0% · Poor 4.0% of 50 bridges

Bridges rated poor

Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.

Bridge	Built	Vehicles/day	Condition
Md 5 over Hilton Run	1936	8,010	Poor
Cornfield Harbor D over Point Lookout Creek	1970	150	Poor

Busiest bridges in the county

Bridge	Built	Vehicles/day	Condition
Md 4 over Kingston Creek	1980	26,801	Fair
Md 5 over St Marys River	1955	22,642	Fair
Md 5 over Mcintosh Run	1935	22,220	Fair
Md 5 over Branch of Mcintosh Run	2017	22,220	Good
Md 5 over Town Run	1990	21,360	Fair
Md 4 over St Marys River	1974	18,051	Fair
Md 237 over Jarboesville Run	2009	17,352	Fair
Md 5 over Glebe Run	1955	12,500	Fair
Md 5 over Moll Dyers Run	1937	12,500	Fair
Md 5 over Eastern Branch	2016	10,000	Fair

Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.

All of Maryland: Maryland bridge conditions by county · every download on the data page.

Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.