Is INTERSTATE 605 Safe?
INTERSTATE 605 in California has a Condition Score of 73/100 (Grade B). The deck is rated 7/9, superstructure 7/9, and substructure 7/9. The bridge is not currently classified as structurally deficient. Built in 1966 (60 years old), it carries approximately 297K vehicles per day.
INTERSTATE 605 carries a B on the BridgeSafety Condition Score with 73/100. Most component ratings are solid; one or two may show wear consistent with the structure’s age, but the bridge is not flagged as structurally deficient.
The bridge was built in 1966 and is now 60 years old, at or past the typical 50-year design life for bridges of its vintage. Maintenance and inspection cycles are correspondingly more involved than for newer structures. INTERSTATE 605 carries an average daily traffic count of 297,000 vehicles, with 14 lane(s) crossing Fairton Street. The owning agency is State Highway Agency; bridge inspection records flow into the federal NBI database annually.
BridgeSafety reads the FHWA National Bridge Inventory (NBI) — the authoritative federal dataset covering every public road bridge longer than 20 feet in the United States. Each bridge record includes age, structural condition by component, traffic load, and the formal sufficiency rating that determines federal funding eligibility.
The Structurally Deficient designation flags bridges where at least one primary component (deck, superstructure, substructure) is rated in poor condition on the FHWA 0-9 scale. FHWA explicitly notes that bridges with this designation remain open and safe when they meet load-rating requirements; the designation signals rehabilitation need, not closure.
What the Condition Score Means
With a Condition Score of 73/100, INTERSTATE 605 earns a B grade. Component ratings are in the "Satisfactory" range on the 0-9 NBI scale, the typical condition for an actively-maintained structure of its age. State DOT inspectors will continue routine biennial inspection cycles; targeted repairs (joint work, deck patching) are usually the operational response at this rating tier.
INTERSTATE 605 is not currently classified as structurally deficient. All three primary components — deck, superstructure, and substructure — rate above 4 on the FHWA NBI 0-9 scale, the threshold for the federal "structurally deficient" label. The bridge remains in the routine inspection cycle (typically every 24 months) without triggering federal rehabilitation funding eligibility.
Component Ratings
| Component | Rating | Scale |
|---|---|---|
| Deck | 7 | /9 |
| Superstructure | 7 | /9 |
| Substructure | 7 | /9 |
| Overall Score | 73/100 | Grade B |
FHWA scale: 9 Excellent, 7 Good, 5 Fair, 4 Poor, lower readings indicate progressively worse condition. Component ratings reflect the most recent inspection submitted to the National Bridge Inventory.
Age and Traffic Context
INTERSTATE 605 dates to 1966, making it 60 years old. The structure is past the 50-year mark commonly used as an FHWA cutoff for older inventory. Bridges in this age range often appear in state DOT replacement plans because cumulative deterioration and changing design standards (lane width, load capacity) make replacement more cost-effective than continued rehabilitation.
INTERSTATE 605 carries roughly 297K vehicles per day, a heavy traffic volume that places it among the higher-priority structures in the inventory for maintenance allocation. Heavy daily traffic accelerates deck wear, joint deterioration, and accumulated fatigue on superstructure elements, which is why busy interstate and arterial bridges often appear on rehabilitation priority lists.
Bridge Details
Frequently Asked Questions
Is INTERSTATE 605 safe to cross?
INTERSTATE 605 remains open to traffic at posted load limits set by the owning state DOT. Its current Condition Score is 73/100 (Grade B). NBI condition ratings describe observed physical condition; they are not closure or safety determinations. State DOTs and the FHWA bridge program are the authoritative sources for any operational restriction on a specific structure. The bridge does not meet the federal definition of "structurally deficient."
What do the deck, superstructure, and substructure ratings mean?
On the FHWA NBI 0-9 scale: 9 is Excellent, 7 Good, 5 Fair, 4 Poor, and 0 means the component has failed. INTERSTATE 605 rates deck 7/9, superstructure 7/9, and substructure 7/9. The deck is the riding surface; the superstructure carries loads from deck to bearings (girders, beams, trusses); the substructure transfers loads to foundations (piers, abutments). A rating of 4 or lower on any of the three triggers the "structurally deficient" classification.
When was INTERSTATE 605 last inspected?
Federal regulation requires inspection at least every 24 months by a certified team leader. Inspection records flow from the California Department of Transportation to the FHWA NBI; the dataset on this page reflects the 2025 federal NBI release, refreshed April 2026. For the most recent inspection report or any operational status (postings, lane closures), the California DOT is the authoritative source.
Is INTERSTATE 605 structurally deficient?
No — INTERSTATE 605 does not currently meet the FHWA "structurally deficient" definition. All three primary components rate above 4 on the NBI 0-9 scale.
Where can I see official inspection records for INTERSTATE 605?
The Federal Highway Administration publishes the underlying inspection data through the National Bridge Inventory (https://www.fhwa.dot.gov/bridge/nbi.cfm). The California DOT publishes additional state-level reporting and operational notices. The ASCE Infrastructure Report Card provides national-level analysis that draws on the same NBI data.