70TH STREET
Carrying 70TH STREET over M BR BLACK RIVER
APPROX 0.50 MI S OF 103RD, Allegan, Michigan
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
70TH STREET in Allegan, Michigan sits above 18% of rated Michigan bridges on inventory load rating (31 t), while its 1971 build year is earlier than 64% of Allegan's recorded-year cohort (244 bridges).
70TH STREET in Allegan, Michigan is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1971, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 4. The lowest applicable rating sets the federal condition category, so this Poor result describes the weakest reported component rather than the structure as a whole. No NBI category is a closure decision or a live crossing-safety verdict.
NBI record plate
Structure MI:000000000000218
INTERSTATE-ERA · TIMBER · LONG-SPAN-RUN · SUB-LED · LOCAL-ADT · STANDARD-LOAD · CAT-POOR
- INTERSTATE-ERA 1950–1979
- TIMBER Wood or timber
- LONG-SPAN-RUN 4 spans
- SUB-LED Substructure-led
- LOCAL-ADT Local ADT
- STANDARD-LOAD Standard load
- CAT-POOR Poor
Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.
Bridge Snapshot: 70TH STREET
The 70TH STREET bridge in Allegan, Michigan carries 70TH STREET over M BR BLACK RIVER. It was built in 1971, making it 55 years old today. The structure is built primarily of wood or timber and spans 4 sections, stretching 31.7 meters (104 feet) end to end. Daily traffic averages 277 vehicles, placing it in the lower-traffic tier of Michigan bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection records show a deck rating of 5/9, superstructure at 5/9, substructure at 4/9. The weakest component sits in poor condition. At least one major component here scores 4 or below, which produces a Poor condition classification under FHWA's current reporting rules.
How 70TH STREET compares
Age against the county: built in 1971, earlier than 155 of Allegan's 244 bridges with a recorded construction year (64%), against a county median build year of 1974. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Michigan bridges with a recorded inventory load rating (11,366 of 11,371 rated).
70TH STREET vs every rated Michigan bridge
Inventory load rating (metric tons), FHWA NBI, this state
31 Top 82% higher than 18% of 11,366 bridges
rated Michigan bridges, bucketed by value
Each bar is a band; taller bars hold more bridges. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source FHWA National Bridge Inventory · August 2026
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Reported 0–9 component ratings from the FHWA NBI. The highlighted component is the lowest reported input to this record’s current condition category; it is not a closure or live crossing-safety decision.
Allegan inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 244 bridges in this county. Orthogonal to this structure's component profile above: a county catalog share, not a live crossing-safety verdict.
Structural Details
- Year Built
- 1971
- Material
- Wood or Timber
- Number of Spans
- 4
- Structure Length
- 31.7 m (104 ft)
- Deck Width
- 9.0 m (30 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 277 vehicles/day
- Structure Number
- 000000000000218
Condition Analysis
- • The deck (driving surface) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
- • The superstructure (beams and supports above the deck) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
- • The substructure (piers and abutments) is in poor condition (4/9), showing advanced deterioration on the inspecting agency's 0-9 scale.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
70TH STREET is in the federal Poor condition category. That is a component-based result, not a closure order.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Understand what Poor condition does and does not mean before drawing conclusions. Poor condition explained
- Compare 70TH STREET against other structures in Allegan and across Michigan. Michigan bridges
- Noticed visible damage or a safety concern? Report it to the agency that owns the bridge, or call 911 in an emergency. How to report a bridge
Condition codes come straight from the FHWA National Bridge Inventory and are not a real-time safety judgment. Only the owning agency, a state DOT, county, or other owner, can post, restrict, or close a bridge.
Frequently Asked Questions
What do the condition ratings mean for 70TH STREET?
70TH STREET in Allegan, Michigan has a deck rating of 5/9, superstructure rating of 5/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.
How often is 70TH STREET inspected?
70TH STREET's responsible agency sets its routine interval under FHWA's risk-based inspection rules; this page does not expose the scheduled interval. It carries about 277 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. 70TH STREET is currently shown as Poor condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for 70TH STREET?
70TH STREET has an NBI inventory load rating of 30.5 metric tons.
Who is responsible for maintaining 70TH STREET?
70TH STREET is owned and maintained by County Highway Agency.
How old is 70TH STREET and does age affect safety?
70TH STREET was built in 1971, making it 55 years old.
Disclaimer: Bridge condition data is from the FHWA NBI and reflects the last reported inspection. A Poor condition rating is not a live declaration that a bridge is closed or unsafe for travel. For current closure, posting, or safety information, contact the responsible transportation agency.
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Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Component ratings, ADT, and condition category on this page are copied from the NBI record for this structure; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.