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M-18|lake St over S Br Au Sable River

Roscommon County, Michigan · rated Fair in the 2025 National Bridge Inventory

United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled August 20, 2026

M-18|lake St over S Br Au Sable River in Roscommon County, Michigan, is rated in fair condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
It was built in 1935 and reconstructed in 1995, making it 90 years old at the 2025 inventory.
It carries about 5,505 vehicles a day (traffic count year 2018).
Its listed owner is the state highway agency.
It is one of 34 of the 42 inventoried bridges in Roscommon County rated fair (81.0%); 0 (0.0%) are rated poor.
A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.

Component ratings


Structure	Prestressed concrete single box beam
Length	about 49 ft
Location	E Lts of Roscommon
NBI structure number	000000000009015
Condition class	Fair

Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.

Bridge	Built	Vehicles/day	Condition
M-18\|m-55\|w Hought over Denton Creek	1959	11,420	Fair
County Rd 100\|SUNS over I-75 SB	1971	9,280	Fair
County Rd 100\|SUNS over I-75 NB	1971	9,280	Fair
M-55 EB Ramp over I-75 NB	1971	7,828	Fair
M-55 WB over I-75 NB	1971	7,828	Fair
I-75 Sb\|m-55 EB over Old 76\|S Saint Helen Rd	1971	7,800	Fair