MERCER SLOUGH
Washington — Condition: Poor
Location
| State | Washington |
| Coordinates | 47.57953, -122.19022 |
| Features Crossed | MERCER SLOUGH |
| Facility Carried | I-90 |
Physical
| Year Built | 1940 |
| Reconstructed | 1970 |
| Length | 857.1 m |
| Structure Type | 2 |
| Owner | State Highway Agency |
Condition Ratings
| Overall | Poor |
| Deck (0–9) | Satisfactory (6) |
| Superstructure (0–9) | Poor (4) |
| Substructure (0–9) | Satisfactory (6) |
Traffic
| Daily Traffic (ADT) | 74,410 vehicles/day |
Location Map
About Bridge Condition Ratings
Bridge condition ratings are assigned by trained inspectors following Federal Highway Administration guidelines. The overall condition (Good, Fair, or Poor) is based on the lowest rating among the deck, superstructure, and substructure components. Ratings use a 0–9 scale where 9 is excellent and 0 is a failed condition. A "Poor" rating does not mean the bridge is unsafe — it indicates the bridge needs attention, may have load restrictions, or is a priority for maintenance or replacement.
About This Bridge Inspection
Bridge inspection data is collected by the Federal Highway Administration (FHWA) under the National Bridge Inspection Standards program. Bridges rated Poor (0-4) are flagged for priority maintenance or replacement.