INTERSTATE 8
INTERSTATE 8 in 11-Sd-008-14.95-Ecj, San Diego County, California received a condition grade of B (63/100). Built in 1961, the bridge carries 189K vehicles daily on INTERSTATE 8 over Mtdb Lrt Sdiv & Marshall.
INTERSTATE 8 carries a B on the BridgeSafety Condition Score with 63/100. 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 1961 and is now 65 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 8 carries an average daily traffic count of 189,000 vehicles, with 10 lane(s) crossing Mtdb Lrt Sdiv & Marshall. 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 65-year-old bridge located 11-Sd-008-14.95-Ecj in San Diego County, California. The bridge carries INTERSTATE 8 over Mtdb Lrt Sdiv & Marshall with 10 traffic lanes, handling approximately 189K vehicles per day. Built in 1961 and reconstructed in 1985, the structure spans 87.5 meters.
The bridge received a Condition Grade of B (63/100) based on Federal Highway Administration inspection data. Its deck is rated 5/9 (fair), superstructure 7/9 (good), and substructure 7/9 (good).
This bridge is owned and maintained by State Highway Agency.
Location Map
Frequently Asked Questions
INTERSTATE 8 has a Condition Score of 63/100 (Grade B). Its deck is rated 5/9, superstructure 7/9, and substructure 7/9 on the NBI scale. The bridge is not classified as structurally deficient.
INTERSTATE 8 was built in 1961 and reconstructed in 1985, making it 65 years old. The average bridge age in the United States is 48 years.
INTERSTATE 8 carries approximately 189K vehicles per day (average daily traffic). The bridge has 10 traffic lanes. It is 87.5 meters long and located on INTERSTATE 8 in 11-Sd-008-14.95-Ecj, San Diego County, California.
No, INTERSTATE 8 is not classified as structurally deficient. All three primary components (deck, superstructure, and substructure) are rated above 4 on the 0-9 NBI scale.
INTERSTATE 8 is located 11-Sd-008-14.95-Ecj in San Diego County, California. The bridge carries INTERSTATE 8 over Mtdb Lrt Sdiv & Marshall. Its coordinates are 32.799347, -116.975861. It is maintained by State Highway Agency.
INTERSTATE 8 carries INTERSTATE 8 over Mtdb Lrt Sdiv & Marshall. The bridge is 87.5 meters long and was built in 1961, with reconstruction in 1985.
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.