Tr 206A over Main Ditch
Mason County, Illinois · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Tr 206A over Main Ditch in Mason County, Illinois, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1956, making it 69 years old at the 2025 inventory.
- It carries about 150 vehicles a day (traffic count year 2024).
- Its listed owner is a town or township highway agency.
- It is one of 52 of the 86 inventoried bridges in Mason County rated fair (60.5%); 3 (3.5%) 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 February 2025, on a 24-month routine inspection cycle.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (40.34331, -89.77193)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Continuous steel stringer or multi-beam girder |
| Length | about 95 ft |
| Location | 3 Mi SE Forest City |
| NBI structure number | 063331000000000 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | February 2025 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Illinois department of transportation.
Busiest bridges in Mason County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 136 / Il 29 over Main Ditch | 1958 | 2,500 | Fair |
| Ill 29 over Allens Grove Ditch | 1959 | 2,450 | Good |
| Fap 614 (il 78) over Ditch | 1978 | 2,250 | Fair |
| Il 29 over Sleepy Hollow Ditch | 1959 | 2,000 | Fair |
| Il 29 over Salt Creek | 2002 | 2,000 | Fair |
| Ill 78 over White Oak Creek | 1931 | 1,750 | Fair |
All bridges nearby: Mason County, IL bridge conditions · every bridge in Mason County · Illinois bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.