IS 270
IS 270 in 1.17 Miles N Of Md 124, Montgomery County, Maryland received a condition grade of B (63/100). Built in 1954, the bridge carries 154K vehicles daily on IS 270 over Gr Seneca CR & Game Pre.
IS 270 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 1954 and is now 72 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. IS 270 carries an average daily traffic count of 154,247 vehicles, with 8 lane(s) crossing Gr Seneca CR & Game Pre. 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
IS 270 is a 72-year-old bridge located 1.17 Miles N Of Md 124 in Montgomery County, Maryland. The bridge carries IS 270 over Gr Seneca CR & Game Pre with 8 traffic lanes, handling approximately 154K vehicles per day. Built in 1954 and reconstructed in 1989, the structure spans 70.4 meters.
The bridge received a Condition Grade of B (63/100) based on Federal Highway Administration inspection data. Its deck is rated 7/9 (good), superstructure 6/9 (fair), and substructure 7/9 (good).
This bridge is owned and maintained by State Highway Agency.
Location Map
Frequently Asked Questions
IS 270 has a Condition Score of 63/100 (Grade B). Its deck is rated 7/9, superstructure 6/9, and substructure 7/9 on the NBI scale. The bridge is not classified as structurally deficient.
IS 270 was built in 1954 and reconstructed in 1989, making it 72 years old. The average bridge age in the United States is 48 years.
IS 270 carries approximately 154K vehicles per day (average daily traffic). The bridge has 8 traffic lanes. It is 70.4 meters long and located on IS 270 in 1.17 Miles N Of Md 124, Montgomery County, Maryland.
No, IS 270 is not classified as structurally deficient. All three primary components (deck, superstructure, and substructure) are rated above 4 on the 0-9 NBI scale.
IS 270 is located 1.17 Miles N Of Md 124 in Montgomery County, Maryland. The bridge carries IS 270 over Gr Seneca CR & Game Pre. Its coordinates are 39.160753, -77.231983. It is maintained by State Highway Agency.
IS 270 carries IS 270 over Gr Seneca CR & Game Pre. The bridge is 70.4 meters long and was built in 1954, with reconstruction in 1989.
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.