To look up bridges, first choose a county and then a road. You will get a list of bridges.
To look up more details on specific bridges, click on the "Route" name hyperlinked in green. The information in this database was provided by the Michigan Department of Transportation.
What the fields mean:
Structurally Deficient (SD) Status - A highway bridge is classified as structurally deficient if the deck, superstructure, substructure, or culvert is rated in "poor" condition (0 to 4 on the NBI rating scale). A bridge can also be classified as structurally deficient if its load carrying capacity is significantly below current design standards or if a waterway below frequently overtops the bridge during floods.
Functionally Obsolete (FO) Status - Highway bridges classified as functionally obsolete are NOT structurally deficient, but their design is outdated. They may have lower load carrying capacity, narrower shoulders or less clearance underneath than bridges built to the current standard.
- 9 - EXCELLENT CONDITION
- 8 - VERY GOOD CONDITION - No problems noted
- 7 - GOOD CONDITION - Some minor problems.
- 6 - SATISFACTORY CONDITION - Structural elements show minor deterioration
- 5 - FAIR CONDITION - All primary structural elements are sound but may have minor corrosion, cracking or chipping. May include minor erosion on bridge piers.
- 4 - POOR CONDITION - Advanced corrosion, deterioration, cracking or chipping. Also significant erosion of concrete bridge piers.
- 3 - SERIOUS CONDITION - Corrosion, deterioration, cracking and chipping, or erosion of concrete bridge piers have seriously affected deck, superstructure, or substructure. Local failures are possible.
- 2 - CRITICAL CONDITION - Advanced deterioration of deck, superstructure, or substructure. May have cracks in steel or concrete, or erosion may have removed substructure support. It may be necessary to close the bridge until corrective action is taken.
- 1 - "IMMINENT" FAILURE CONDITION - Major deterioration or corrosion in deck, superstructure, or substructure, or obvious vertical or horizontal movement affecting structure stability. Bridge is closed to traffic but corrective action may put back in light service.
- 0 - FAILED CONDITION - Out of service - beyond corrective action
- N - Not applicable
Superstructure: The portion of the bridge that supports the deck and connects one substructure element to another.
Substructure: The portion of the bridge that supports the superstructure and distributes all bridge loads to below-ground bridge footings.
Culvert: A pipe or small structure used for drainage under a road, railroad or other embankment. A culvert with a span length greater than 20 feet is included in the National Bridge Inventory.