IS 495
IS 495 in 0.55 Mile East Of Md 97, Montgomery County, Maryland received a condition grade of F (0/100). Built in 1960, the bridge carries 232K vehicles daily on IS 495 over Sligo Creek. It is classified as structurally deficient.
IS 495 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 1960 and is now 66 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 495 carries an average daily traffic count of 232,010 vehicles, with 8 lane(s) crossing Sligo 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
IS 495 is a 66-year-old bridge located 0.55 Mile East Of Md 97 in Montgomery County, Maryland. The bridge carries IS 495 over Sligo Creek with 8 traffic lanes, handling approximately 232K vehicles per day. Built in 1960, the structure spans 10.1 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
IS 495 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.
IS 495 was built in 1960, making it 66 years old. The average bridge age in the United States is 48 years.
IS 495 carries approximately 232K vehicles per day (average daily traffic). The bridge has 8 traffic lanes. It is 10.1 meters long and located on IS 495 in 0.55 Mile East Of Md 97, Montgomery County, Maryland.
Yes, IS 495 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.
IS 495 is located 0.55 Mile East Of Md 97 in Montgomery County, Maryland. The bridge carries IS 495 over Sligo Creek. Its coordinates are 39.014911, -77.032133. It is maintained by State Highway Agency.
IS 495 carries IS 495 over Sligo Creek. The bridge is 10.1 meters long and was built in 1960.
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.