US 40 over Patapsco River
Baltimore County, Maryland · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US 40 over Patapsco River in Baltimore County, Maryland, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 1936 and reconstructed in 2011, making it 89 years old at the 2025 inventory.
- It carries about 37,530 vehicles a day (traffic count year 2009).
- Its listed owner is the state highway agency.
- It is one of 236 of the 786 inventoried bridges in Baltimore County rated good (30.0%); 22 (2.8%) are rated poor.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (39.29506, -76.77884)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 7 | Good condition |
| Superstructure | 7 | Good condition |
| Substructure | 8 | Very good condition |
Bridge details
| Structure | Concrete deck arch |
| Length | about 333 ft |
| Location | on Howard Co Line |
| NBI structure number | 100000030109010 |
| Condition class | Good |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Maryland department of transportation.
Busiest bridges in Baltimore County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Is 83/IS 695 over Thornton Road | 1954 | 222,500 | Fair |
| Is 695 over Md 26 | 2012 | 210,600 | Good |
| Is 695 & Belmont A over Dead Run | 1961 | 206,852 | Fair |
| Is 695 over Mta Light Rail | 1955 | 205,485 | Fair |
| Is 695 over Security Boulevard | 1961 | 203,902 | Good |
| Is 695 over Dogwood Road | 1961 | 203,902 | Fair |
All bridges nearby: Baltimore County, MD bridge conditions · every bridge in Baltimore County · Maryland bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.