FOREST ROAD 400
Carrying FOREST ROAD 400 over BUNKER GULCH
E OF JCT ROAD 440, Mendocino, California
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: FOREST ROAD 400
The FOREST ROAD 400 bridge in Mendocino, California carries FOREST ROAD 400 over BUNKER GULCH. It was built in 1992, making it 34 years old today. The structure is built primarily of steel and spans 1 section, stretching 9.8 meters (32 feet) end to end. Daily traffic averages 10 vehicles, placing it in the lower-traffic tier of California bridges. It is owned and maintained by State Park/Forest/Reservation.
The latest FHWA inspection records show a deck rating of 7/9, superstructure at 4/9, substructure at 7/9. The weakest component sits in poor condition. At least one major component here scores 4 or below, which produces a Poor condition classification under FHWA's current reporting rules. Its NBI inventory load rating is 33.0 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How FOREST ROAD 400 compares
Live comparison across California.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1992
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 9.8 m (32 ft)
- Deck Width
- 4.9 m (16 ft)
- Owner
- State Park/Forest/Reservation
- Avg Daily Traffic
- 10 vehicles/day
- Structure Number
- 10F0037
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • At 7/9, the deck (driving surface) is in good shape and shows no significant wear.
- • At 4/9, the superstructure (beams and supports above the deck) is in poor shape, with advanced wear flagged for priority repair.
- • The substructure (piers and abutments) is in good condition (7/9), showing no significant deterioration.
How to read this record
FOREST ROAD 400 is in the federal Poor condition category. That is a component-based result, not a closure order.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Understand what Poor condition does and does not mean before drawing conclusions. Poor condition explained
- Compare FOREST ROAD 400 against other structures in Mendocino and across California. California bridges
- Noticed visible damage or a safety concern? Report it to the agency that owns the bridge, or call 911 in an emergency. How to report a bridge
Condition codes come straight from the FHWA National Bridge Inventory and are not a real-time safety judgment. Only the owning agency, a state DOT, county, or other owner, can post, restrict, or close a bridge.
Frequently Asked Questions
What do the condition ratings mean for FOREST ROAD 400?
FOREST ROAD 400 in Mendocino, California has a deck rating of 7/9, superstructure rating of 4/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is FOREST ROAD 400 inspected?
FOREST ROAD 400's responsible agency sets its routine interval under FHWA's risk-based inspection rules; this page does not expose the scheduled interval. It carries about 10 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. FOREST ROAD 400 is currently shown as Poor condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for FOREST ROAD 400?
FOREST ROAD 400 has an NBI inventory load rating of 33.0 metric tons.
Who is responsible for maintaining FOREST ROAD 400?
FOREST ROAD 400 is owned and maintained by State Park/Forest/Reservation.
How old is FOREST ROAD 400 and does age affect safety?
FOREST ROAD 400 was built in 1992, making it 34 years old.
Disclaimer: Bridge condition data is from the FHWA NBI and reflects the last reported inspection. A Poor condition rating is not a live declaration that a bridge is closed or unsafe for travel. For current closure, posting, or safety information, contact the responsible transportation agency.
Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.