Maryland Bridges
5,484 highway bridges across 24 counties · NBI 2024 data
About Maryland's Bridge Infrastructure
Maryland maintains 5,484 highway bridges across 24 counties, forming critical links in the state's transportation network. With an average construction year of 1972, the typical bridge in Maryland is approximately 54 years old—5 years older than the national average of 49 years. The state's oldest bridge dates back to 1809, representing over a century of service and offering a window into historic bridge engineering practices.
Currently, 4.6% of Maryland's bridges are rated in poor condition, better than the national average of 6.8%. This indicates relatively strong investment in bridge maintenance and replacement programs. A "poor" condition rating indicates significant deterioration requiring attention, though these bridges remain safe for travel at their posted limits. Federal regulations require bridge inspections at least every 24 months to ensure public safety.
Bridge conditions in Maryland reflect decades of infrastructure investment decisions shaped by geography, climate, traffic demands, and available funding. Bridges here carry 21,243 vehicles daily on average—167% higher than the national average—placing greater demands on structural maintenance. The state's 116,370,145 total daily bridge crossings underscore how essential this infrastructure is to daily commerce and commuting.
The material composition of Maryland's bridge inventory reflects regional construction practices and evolving engineering standards. The predominant construction material is steel, accounting for 59.1% of all structures. Material choice affects maintenance requirements, expected lifespan, and vulnerability to environmental factors specific to the region. Understanding these patterns helps transportation planners allocate resources effectively and prioritize infrastructure investments.
Worst-Rated Bridges
View all 250 poor-condition bridges →250 of 5,484 Maryland bridges have a rating of 4 or below. Rating 4 = advanced deterioration.
| # | Bridge | Rating | Location | Built | Daily Traffic |
|---|---|---|---|---|---|
| 1 | MILL STREET over ROCK RUN Critical condition requiring immediate attention. At 86 years old, this is among Maryland's oldest structures. | 0 | Cecil County Co. · .01 MI S. OF RACE STREET | 1940 | 100 |
| 2 | WASHINGTON STREET over CSXT RAILROAD Critical condition requiring immediate attention. At 96 years old, this is among Maryland's oldest structures. | 1 | Allegany County Co. · 0.2 MI W OF CUMBERLAND ST | 1930 | 110 |
| 3 | BACK LANDING ROAD over HUNTING CREEK Critical condition requiring immediate attention. At 85 years old, this is among Maryland's oldest structures. | 1 | Dorchester County Co. · ON CAROLINE COUNTY LINE | 1941 | — |
| 4 | FAYETTE STREET over CSXT RAILROAD Critical condition requiring immediate attention. At 141 years old, this is among Maryland's oldest structures. | 2 | Allegany County Co. · .08 MI W OF CUMBERLAND ST | 1885 | 109 |
| 5 | MOHRS LANE over CSX RAILROAD Critical condition requiring immediate attention. At 114 years old, this is among Maryland's oldest structures. | 2 | Baltimore County Co. · 0.1 MI NW OF US RTE 40 | 1912 | 1,600 |
| 6 | REMINGTON AVENUE over STONEY RUN Critical condition requiring immediate attention. At 126 years old, this is among Maryland's oldest structures. | 2 | Baltimore city Co. · 0.9 MI N OF NORTH AVE | 1900 | 4,280 |
| 7 | RUSSELL STREET over CSX Critical condition requiring immediate attention. Built 63 years ago, approaching the end of typical service life. Serves 46,276 vehicles per day. | 2 | Baltimore city Co. · 0.2 MI S OF I-95 | 1963 | 46,276 |
| 8 | SISSON STREET over CSX Critical condition requiring immediate attention. At 112 years old, this is among Maryland's oldest structures. | 2 | Baltimore city Co. · 0.3 MI W OF MARYLAND AVE | 1914 | 6,500 |
| 9 | BEECHWOOD ROAD over KOONTZ RUN Serious deterioration affecting structural elements. Low-traffic rural crossing. | 3 | Allegany County Co. · 1 MILE N. of DOUGLAS HILL | 1983 | 56 |
| 10 | CUMBERLAND STREET over CSXT RAILROAD Serious deterioration affecting structural elements. At 97 years old, this is among Maryland's oldest structures. | 3 | Allegany County Co. · 0.6 MI E OF WASHINGTON ST | 1929 | 110 |
Bridges by County
Baltimore County holds 14% of Maryland's bridges. Garrett County has the highest deficiency rate.
| County | Bridges ↓ | Condition | Poor | Poor % | Avg ADT |
|---|---|---|---|---|---|
| Baltimore County Largest bridge inventory in Maryland. High-traffic area averaging 31,211 vehicles per bridge daily. | 783 | 253 494 | 25 | 3.2% | 31,211 |
| Prince George's County One of Maryland's largest bridge inventories. High-traffic area averaging 37,903 vehicles per bridge daily. | 576 | 186 363 | 18 | 3.1% | 37,903 |
| Montgomery County One of Maryland's largest bridge inventories. High-traffic area averaging 27,301 vehicles per bridge daily. | 515 | 166 325 | 25 | 4.9% | 27,301 |
| Frederick County | 486 | 157 307 | 13 | 2.7% | 13,808 |
| Anne Arundel County Below-average deficiency rate. High-traffic area averaging 31,842 vehicles per bridge daily. | 389 | 126 245 | 6 | 1.5% | 31,842 |
| Baltimore city Poor condition rate significantly above state average. High-traffic area averaging 27,243 vehicles per bridge daily. | 374 | 121 236 32 | 32 | 8.6% | 27,243 |
| Howard County High-traffic area averaging 29,460 vehicles per bridge daily. | 309 | 100 195 18 | 18 | 5.8% | 29,460 |
| Washington County | 300 | 97 189 | 14 | 4.7% | 16,214 |
| Harford County | 275 | 89 174 | 13 | 4.7% | 9,650 |
| Allegany County | 245 | 79 155 15 | 15 | 6.1% | 6,755 |
Infrastructure Profile
| Average bridge age | 54 years |
| Average year built | 1972 |
| Oldest bridge | 1809 |
| Newest bridge | 2024 |
| Avg daily traffic/bridge | 21,243 |
| Total daily crossings | 116.4M |
Maryland vs. National Average
Inspections typically occur every 24 months. Structurally deficient does not mean unsafe.