INTERSTATE 8
INTERSTATE 8 in 11-Sd-008-10.61-Lmsa, San Diego County, California received a condition grade of F (0/100). Built in 1939, the bridge carries 175K vehicles daily on INTERSTATE 8 over Alvarado Canyon Creek. It is classified as structurally deficient.
INTERSTATE 8 carries an F on the BridgeSafety Condition Score with 0/100 — the bottom tier of the FHWA NBI distribution. Component ratings flag the structure for near-term rehabilitation or replacement; the bridge may remain open to traffic but is on the priority list for action.
The bridge was built in 1939, making it 87 years old — well beyond the typical 50-year design life of bridges constructed in that era. Bridges of this vintage usually need substantial rehabilitation or replacement once their original components have aged out, regardless of current condition ratings. INTERSTATE 8 carries an average daily traffic count of 175,000 vehicles, with 9 lane(s) crossing Alvarado Canyon Creek. The owning agency is State Highway Agency; bridge inspection records flow into the federal NBI database annually.
Component Ratings
The riding surface, evaluated for cracking, spalling, and wear
Beams, girders, and trusses that support the deck
Piers, abutments, and foundations below the deck
Bridge Details
About This Bridge
INTERSTATE 8 is a 87-year-old bridge located 11-Sd-008-10.61-Lmsa in San Diego County, California. The bridge carries INTERSTATE 8 over Alvarado Canyon Creek with 9 traffic lanes, handling approximately 175K vehicles per day. Built in 1939 and reconstructed in 1961, the structure spans 9.8 meters.
The bridge received a Condition Grade of F (0/100) based on Federal Highway Administration inspection data. Its deck is rated 0/9 (serious), superstructure 0/9 (serious), and substructure 0/9 (serious). The bridge is classified as structurally deficient, meaning at least one major component is rated 4 or below, this signals a need for repair or replacement but does not necessarily indicate an immediate safety hazard.
This bridge is owned and maintained by State Highway Agency.
Location Map
Frequently Asked Questions
INTERSTATE 8 has a Condition Score of 0/100 (Grade F). Its deck is rated 0/9, superstructure 0/9, and substructure 0/9 on the NBI scale. The bridge is classified as structurally deficient.
INTERSTATE 8 was built in 1939 and reconstructed in 1961, making it 87 years old. The average bridge age in the United States is 48 years.
INTERSTATE 8 carries approximately 175K vehicles per day (average daily traffic). The bridge has 9 traffic lanes. It is 9.8 meters long and located on INTERSTATE 8 in 11-Sd-008-10.61-Lmsa, San Diego County, California.
Yes, INTERSTATE 8 is classified as structurally deficient because at least one of its primary components (deck, superstructure, or substructure) is rated 4 or below on the 0-9 NBI scale. This does not necessarily mean it is unsafe, but it requires significant repair or replacement.
INTERSTATE 8 is located 11-Sd-008-10.61-Lmsa in San Diego County, California. The bridge carries INTERSTATE 8 over Alvarado Canyon Creek. Its coordinates are 32.772942, -117.029553. It is maintained by State Highway Agency.
INTERSTATE 8 carries INTERSTATE 8 over Alvarado Canyon Creek. The bridge is 9.8 meters long and was built in 1939, with reconstruction in 1961.
Condition Score is calculated from deck (33%), superstructure (33%), and substructure (34%) NBI ratings with an age penalty for bridges over 50 years.
Source: FHWA National Bridge Inventory, 2026.