Minnesota Bridges
13,532 highway bridges across 87 counties · NBI 2024 data
About Minnesota's Bridge Infrastructure
Minnesota maintains 13,532 highway bridges across 87 counties, forming critical links in the state's transportation network. With an average construction year of 1986, the typical bridge in Minnesota is approximately 40 years old—9 years newer than the national average of 49 years. The state's oldest bridge dates back to 1884, representing over a century of service and offering a window into historic bridge engineering practices.
Currently, 4.4% of Minnesota'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 Minnesota reflect decades of infrastructure investment decisions shaped by geography, climate, traffic demands, and available funding. Average daily traffic of 4,197 vehicles per bridge is below the national average, which can reduce wear but still requires consistent maintenance investment. The state's 56,785,237 total daily bridge crossings underscore how essential this infrastructure is to daily commerce and commuting.
The material composition of Minnesota's bridge inventory reflects regional construction practices and evolving engineering standards. The predominant construction material is concrete, accounting for 52.0% 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 601 poor-condition bridges →601 of 13,532 Minnesota bridges have a rating of 4 or below. Rating 4 = advanced deterioration.
| # | Bridge | Rating | Location | Built | Daily Traffic |
|---|---|---|---|---|---|
| 1 | CSAH 1 over RED RIVER OF THE NORTH Critical condition requiring immediate attention. At 87 years old, this is among Minnesota's oldest structures. | 0 | Polk County Co. · 2.5 MI W OF JCT TH 75 | 1939 | 205 |
| 2 | T 144 over TOAD RIVER Critical condition requiring immediate attention. At 86 years old, this is among Minnesota's oldest structures. Low-traffic rural crossing. | 0 | Becker County Co. · 0.3 MI E OF JCT TH 87 | 1940 | 28 |
| 3 | T 115 over N BR MID FK ZUMBRO RIVER Critical condition requiring immediate attention. At 96 years old, this is among Minnesota's oldest structures. Low-traffic rural crossing. | 0 | Dodge County Co. · 0.5 MI N OF JCT TH 57 | 1930 | 14 |
| 4 | T 1331 over NOKASIPPI RIVER Critical condition requiring immediate attention. At 118 years old, this is among Minnesota's oldest structures. Low-traffic rural crossing. | 0 | Crow Wing County Co. · 0.2 MI N OF JCT CSAH 2 | 1908 | 20 |
| 5 | T 310 over N BR TWO RIVERS Critical condition requiring immediate attention. At 119 years old, this is among Minnesota's oldest structures. Low-traffic rural crossing. | 0 | Kittson County Co. · 0.3 MI E OF JCT CSAH 1 | 1907 | 12 |
| 6 | T 187 over OKABENA CREEK Critical condition requiring immediate attention. At 121 years old, this is among Minnesota's oldest structures. Low-traffic rural crossing. | 0 | Jackson County Co. · 0.3 MI S OF JCT CSAH 18 | 1905 | 10 |
| 7 | M 12 over STREAM Critical condition requiring immediate attention. At 91 years old, this is among Minnesota's oldest structures. Low-traffic rural crossing. | 0 | Goodhue County Co. · IN ZUMBROTA | 1935 | 60 |
| 8 | CR 51 over REDWOOD RIVER Critical condition requiring immediate attention. Built 64 years ago, approaching the end of typical service life. Low-traffic rural crossing. | 1 | Redwood County Co. · 0.9 MI S OF JCT CSAH 30 | 1962 | 15 |
| 9 | UT 2233 over SWAN RIVER Critical condition requiring immediate attention. At 109 years old, this is among Minnesota's oldest structures. Low-traffic rural crossing. | 1 | Itasca County Co. · 0.4 MI S OF JCT CSAH 10 | 1917 | 25 |
| 10 | M 340 over STREAM Critical condition requiring immediate attention. Built 58 years ago, approaching the end of typical service life. Low-traffic rural crossing. | 1 | St. Louis County Co. · 0.1 MI W OF JCT CR444 | 1968 | 20 |
Bridges by County
Hennepin County holds 7% of Minnesota's bridges. Redwood County has the highest deficiency rate.
| County | Bridges ↓ | Condition | Poor | Poor % | Avg ADT |
|---|---|---|---|---|---|
| Hennepin County Largest bridge inventory in Minnesota. High-traffic area averaging 21,933 vehicles per bridge daily. | 936 | 531 364 | 38 | 4.1% | 21,933 |
| St. Louis County One of Minnesota's largest bridge inventories. Poor condition rate significantly above state average. | 663 | 376 258 45 | 45 | 6.8% | 2,679 |
| Olmsted County One of Minnesota's largest bridge inventories. Below-average deficiency rate. | 365 | 207 142 | 5 | 1.4% | 5,412 |
| Fillmore County Primarily rural road network. | 348 | 197 135 | 10 | 2.9% | 450 |
| Mower County Poor condition rate significantly above state average. | 343 | 194 133 28 | 28 | 8.2% | 1,124 |
| Ramsey County High-traffic area averaging 23,691 vehicles per bridge daily. | 341 | 193 133 22 | 22 | 6.5% | 23,691 |
| Goodhue County | 333 | 189 130 20 | 20 | 6.0% | 2,089 |
| Nobles County Below-average deficiency rate. | 304 | 172 118 | 5 | 1.6% | 606 |
| Polk County | 268 | 152 104 | 9 | 3.4% | 532 |
| Rock County | 265 | 150 103 | 6 | 2.3% | 772 |
Infrastructure Profile
| Average bridge age | 40 years |
| Average year built | 1986 |
| Oldest bridge | 1884 |
| Newest bridge | 2023 |
| Avg daily traffic/bridge | 4,197 |
| Total daily crossings | 56.8M |
Minnesota vs. National Average
Inspections typically occur every 24 months. Structurally deficient does not mean unsafe.