INTERSTATE 15
INTERSTATE 15 in 11-Sd-015-1.49-Sd, San Diego County, California received a condition grade of C (58/100). Built in 1951, the bridge carries 138K vehicles daily on INTERSTATE 15 over Mtdb Lrt Sdivrr Imperial.
INTERSTATE 15 carries a C on the BridgeSafety Condition Score with 58/100. Component ratings sit in the middle of the FHWA NBI distribution; rehabilitation programming is likely on the owning agency’s medium-term horizon.
The bridge was built in 1951 and is now 75 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 15 carries an average daily traffic count of 138,000 vehicles, with 6 lane(s) crossing Mtdb Lrt Sdivrr Imperial. 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 15 is a 75-year-old bridge located 11-Sd-015-1.49-Sd in San Diego County, California. The bridge carries INTERSTATE 15 over Mtdb Lrt Sdivrr Imperial with 6 traffic lanes, handling approximately 138K vehicles per day. Built in 1951 and reconstructed in 1996, the structure spans 98.1 meters.
The bridge received a Condition Grade of C (58/100) 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 15 has a Condition Score of 58/100 (Grade C). 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 15 was built in 1951 and reconstructed in 1996, making it 75 years old. The average bridge age in the United States is 48 years.
INTERSTATE 15 carries approximately 138K vehicles per day (average daily traffic). The bridge has 6 traffic lanes. It is 98.1 meters long and located on INTERSTATE 15 in 11-Sd-015-1.49-Sd, San Diego County, California.
No, INTERSTATE 15 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 15 is located 11-Sd-015-1.49-Sd in San Diego County, California. The bridge carries INTERSTATE 15 over Mtdb Lrt Sdivrr Imperial. Its coordinates are 32.706125, -117.120308. It is maintained by State Highway Agency.
INTERSTATE 15 carries INTERSTATE 15 over Mtdb Lrt Sdivrr Imperial. The bridge is 98.1 meters long and was built in 1951, with reconstruction in 1996.
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.