Maryland Bridges

5,484 highway bridges across 24 counties · NBI 2024 data

4.6% in poor condition
National avg: 6.8%
1,771
3,463
250
Good: 1,771 (32.3%) Fair: 3,463 (63.1%) Poor: 250 (4.6%)

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.

250 of 5,484 Maryland bridges have a rating of 4 or below. Rating 4 = advanced deterioration.

#BridgeRatingLocationBuiltDaily Traffic
1MILL 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 STREET1940100
2WASHINGTON 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 ST1930110
3BACK 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 LINE1941
4FAYETTE 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 ST1885109
5MOHRS 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 4019121,600
6REMINGTON 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 AVE19004,280
7RUSSELL 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-95196346,276
8SISSON 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 AVE19146,500
9BEECHWOOD ROAD
over KOONTZ RUN
Serious deterioration affecting structural elements. Low-traffic rural crossing.
3
Allegany County Co. · 1 MILE N. of DOUGLAS HILL198356
10CUMBERLAND 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 ST1929110

Bridges by County

Baltimore County holds 14% of Maryland's bridges. Garrett County has the highest deficiency rate.

CountyBridgesConditionPoorPoor %Avg ADT
Baltimore County
Largest bridge inventory in Maryland. High-traffic area averaging 31,211 vehicles per bridge daily.
783
253
494
253.2%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
183.1%37,903
Montgomery County
One of Maryland's largest bridge inventories. High-traffic area averaging 27,301 vehicles per bridge daily.
515
166
325
254.9%27,301
Frederick County486
157
307
132.7%13,808
Anne Arundel County
Below-average deficiency rate. High-traffic area averaging 31,842 vehicles per bridge daily.
389
126
245
61.5%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
328.6%27,243
Howard County
High-traffic area averaging 29,460 vehicles per bridge daily.
309
100
195
18
185.8%29,460
Washington County300
97
189
144.7%16,214
Harford County275
89
174
134.7%9,650
Allegany County245
79
155
15
156.1%6,755

Infrastructure Profile

Key Metrics
Average bridge age54 years
Average year built1972
Oldest bridge1809
Newest bridge2024
Avg daily traffic/bridge21,243
Total daily crossings116.4M
Rating Distribution (0–9 scale)
0–4 = Poor · 5–6 = Fair · 7–9 = Good
Construction Materials
Steel3,243(59.1%)
Concrete1,436(26.2%)
Prestressed Concrete542(9.9%)
Wood/Timber175(3.2%)
Metal (Other)42(0.8%)
Masonry40(0.7%)
Other6(0.1%)

Maryland vs. National Average

Poor Condition
4.6%
National: 6.8%✓ Better
Good Condition
32.3%
National: 44.1%✗ Worse
Average Age
54 yr
National: 49 yr✗ Worse
Avg Daily Traffic
21,243
National: 7,954✓ Better
Data Source: Federal Highway Administration, National Bridge Inventory 2024. Bridge conditions rated 0–9 per FHWA Recording and Coding Guide. "Poor" = rating ≤ 4 on deck, superstructure, substructure, or culvert.
Inspections typically occur every 24 months. Structurally deficient does not mean unsafe.
Maryland Bridges — 5,484 Bridges, 4.6% Poor | BridgeReport.org