Frost Street over Dowagiac River
Cass County, Michigan · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Frost Street over Dowagiac River in Cass County, Michigan, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 3 (serious condition) on the 0-9 scale.
- It was built in 1930, making it 95 years old at the 2025 inventory.
- It carries about 56 vehicles a day (traffic count year 2019).
- Its listed owner is the county highway agency.
- It is one of 8 of the 53 inventoried bridges in Cass County rated poor (15.1%); 8 (15.1%) are rated poor.
- Its traffic status in the 2025 inventory is posted for load (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated October 2024, on a 12-month routine inspection cycle.
- It is coded scour critical (NBI item 113 = 3): scour critical: foundations unstable for the assessed or calculated scour.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (41.97083, -86.18009)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 4 | 4 | Poor condition |
| Superstructure | 3 | 3 | Serious condition |
| Substructure | 4 | 4 | Poor condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 46 ft |
| Location | 4 Mi W of M-51 |
| NBI structure number | 000000000001454 |
| Condition class | Poor |
| Traffic status (item 41) | Posted for load |
| Last inspection (item 90) | October 2024 |
| Inspection interval (item 91) | 12 months |
| Scour (item 113) | 3: scour critical: foundations unstable for the assessed or calculated scour |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in Cass County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US-12 over M-60 | 1960 | 9,010 | Fair |
| M-51 over Dowagiac Creek | 1949 | 8,127 | Fair |
| US-12 over Christiana Creek | 1941 | 8,072 | Fair |
| US-12 over Brandywine Creek | 1982 | 7,438 | Fair |
| M-62 over Dowagiac Creek | 1950 | 7,355 | Fair |
| US-12 over Valley Creek | 2011 | 7,350 | Good |
All bridges nearby: Cass County, MI bridge conditions · every bridge in Cass County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.