Bridge conditions in Shiawassee County, Michigan
163 inventoried bridges · 15 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
15 of the 163 bridges the federal inventory lists in Shiawassee County are rated poor; the rest split 72 good and 76 fair.
- 15 of the 163 bridges in Shiawassee County, Michigan, are rated in poor condition (9.2%) in the 2025 National Bridge Inventory, as of .
- 72 bridges (44.2%) are rated good and 76 (46.6%) fair.
- The median Shiawassee County bridge was built in 1986.
- The busiest poor-rated bridge is I-69 EB over Huron & Eastern RR (built 1961), carrying about 14,378 vehicles a day.
Good 44.2% · Fair 46.6% · Poor 9.2% of 163 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 |
|---|---|---|---|
| I-69 EB over Huron & Eastern RR | 1961 | 14,378 | Poor |
| I-69 EB over Cn RR & Reed Rd | 1961 | 13,840 | Poor |
| I-69 WB over Cn RR & Reed Rd | 1961 | 13,840 | Poor |
| New Lothrop Road over Shiawassee River | 1955 | 2,055 | Poor |
| Durand Road over Northwood Creek | 1930 | 1,409 | Poor |
| Main St over Holly Drain | 1965 | 1,209 | Poor |
| Bennington Road over Shiawassee River | 1985 | 1,096 | Poor |
| Bennington Road over Bear Creek | 1925 | 1,026 | Poor |
| Bath Road over S Br Lookingglass River | 1925 | 910 | Poor |
| Vernon Rd over I-69 | 1966 | 800 | Poor |
| Newburg Rd over I-69 | 1961 | 674 | Poor |
| Bancroft Rd over I-69 | 1966 | 370 | Poor |
| Lehring Rd over Shiawassee River | 1975 | 360 | Poor |
| Shipman Rd over Rushbed Creek | 1930 | 144 | Poor |
| Vernon Rd over Porter Creek | 1938 | 135 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-69 EB over Looking Glass River | 1961 | 192,000 | Fair |
| I-69 WB over Looking Glass River | 1961 | 192,000 | Fair |
| I-69 EB over Holly Drain | 1961 | 192,000 | Fair |
| I-69 WB over Holly Drain | 1961 | 192,000 | Fair |
| Britton Rd over I-69 | 1989 | 25,000 | Fair |
| M-21 over Shiawassee River | 1970 | 22,689 | Fair |
| I-69 EB over Vermillion Creek | 1989 | 20,138 | Fair |
| I-69 WB over Vermillion Creek | 1989 | 20,138 | Fair |
| I-69 EB over Shaftsburg Rd | 1989 | 20,138 | Fair |
| I-69 EB over Bath Rd | 1988 | 20,138 | Fair |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of Michigan: Michigan 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.