Frohling Rd over S Br Kishwaukee
McHenry County, Illinois · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Frohling Rd over S Br Kishwaukee in McHenry County, Illinois, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 4 (poor condition) on the 0-9 scale.
- It was built in 1978, making it 47 years old at the 2025 inventory.
- It carries about 325 vehicles a day (traffic count year 2021).
- Its listed owner is a town or township highway agency.
- It is one of 48 of the 227 inventoried bridges in McHenry County rated poor (21.1%); 48 (21.1%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (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 24-month routine inspection cycle.
- 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 → (42.21317, -88.47484)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 4 | 4 | Poor condition |
| Superstructure | 4 | 4 | Poor condition |
| Substructure | 8 | 8 | Very good condition |
Bridge details
| Structure | Prestressed concrete multiple box beam |
| Length | about 51 ft |
| Location | 1.1 Mi SE of Seemann |
| NBI structure number | 056312500000000 |
| Condition class | Poor |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Illinois department of transportation.
Busiest bridges in McHenry County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Il 62 over Fox River | 1988 | 43,100 | Fair |
| Il 31 over RR - UP | 1971 | 34,400 | Fair |
| Algonquin Road over Woods Creek | 2004 | 31,600 | Fair |
| Algonquin Road over Crystal Creek | 2004 | 31,600 | Fair |
| Algonquin Road over Gravel Pit Creek | 2004 | 31,600 | Fair |
| Rakow Rd (ch V-29) over Crystal Creek | 1994 | 30,600 | Good |
All bridges nearby: McHenry County, IL bridge conditions · every bridge in McHenry County · Illinois bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.