INTERSTATE 15 SB
INTERSTATE 15 SB in 11-Sd-015-M17.31-Sd, San Diego County, California received a condition grade of B (77/100). Built in 1975, the bridge carries 148K vehicles daily on INTERSTATE 15 SB over Mercy Road.
INTERSTATE 15 SB carries a B on the BridgeSafety Condition Score with 77/100. 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 1975 and is now 51 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 SB carries an average daily traffic count of 148,000 vehicles, with 9 lane(s) crossing Mercy Road. 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 SB is a 51-year-old bridge located 11-Sd-015-M17.31-Sd in San Diego County, California. The bridge carries INTERSTATE 15 SB over Mercy Road with 9 traffic lanes, handling approximately 148K vehicles per day. Built in 1975 and reconstructed in 2009, the structure spans 44.8 meters.
The bridge received a Condition Grade of B (77/100) based on Federal Highway Administration inspection data. Its deck is rated 7/9 (good), 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 SB has a Condition Score of 77/100 (Grade B). Its deck is rated 7/9, superstructure 7/9, and substructure 7/9 on the NBI scale. The bridge is not classified as structurally deficient.
INTERSTATE 15 SB was built in 1975 and reconstructed in 2009, making it 51 years old. The average bridge age in the United States is 48 years.
INTERSTATE 15 SB carries approximately 148K vehicles per day (average daily traffic). The bridge has 9 traffic lanes. It is 44.8 meters long and located on INTERSTATE 15 SB in 11-Sd-015-M17.31-Sd, San Diego County, California.
No, INTERSTATE 15 SB 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 SB is located 11-Sd-015-M17.31-Sd in San Diego County, California. The bridge carries INTERSTATE 15 SB over Mercy Road. Its coordinates are 32.936575, -117.111544. It is maintained by State Highway Agency.
INTERSTATE 15 SB carries INTERSTATE 15 SB over Mercy Road. The bridge is 44.8 meters long and was built in 1975, with reconstruction in 2009.
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.