County profile · official public datasets

Delta County, MI

84 public highway bridges tracked in the FHWA National Bridge Inventory: 38.1% rated Good, 60.7% Fair, 1.2% Poor.

84
Public bridges
38.1%
Good condition
1.2%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Delta County posts a top-10% lowest Poor-condition share among rated counties in the state across rated county bridge inventory.

Top 6%
lowest Poor share in state
1.2%
Poor-condition share
84
public highway bridges
1974
avg year built

Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.

Delta County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Delta County ranks #5 of 83 Michigan counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 1.2%). Delta County, Michigan contains 84 public highway bridges. Roughly 38.1% are rated “Good,” 60.7% “Fair,” and 1.2% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.

Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

Total bridges

84

Public highway bridges in Delta County

Good condition

38.1%

32 of 84 rated 7-9

Fair condition

60.7%

51 of 84 rated 5-6

Poor condition

1.2%

1 of 84 rated 4 or below

In-state Poor-share rank

#5 of 83

Among Michigan counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 84 NBI-tracked bridges by lowest applicable component rating.

Good
38.1% (32)
Fair
60.7% (51)
Poor
1.2% (1)

Delta County's Poor-condition bridges carry 444 vehicle crossings a day

That is 0.2% of the county's reported daily bridge traffic on 1.2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 444 crossings a day against 2,163 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.

Computed over the 84 of 84 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

54.8% of Delta County's bridges have passed the 50-year mark

46 of the 84 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 38.1% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.

Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.

One structure carries 100% of the county's Poor-condition bridge traffic

ROUTE 410 over TEN MILE CREEK, built 1939, carries 444 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 1-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 444 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Delta County's bridges were built

84 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1970s, when 17 of the county's bridges still in the inventory were built, which is 20.2% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1974) matches the Michigan average (1976).

Source FHWA National Bridge Inventory (year built) As of 2024 NBI release

How Delta County compares with Michigan's closest counties by inventory size

The 5 Michigan counties nearest Delta County in number of bridges, with their condition splits. Its 1.2% Poor share is the 1st-lowest of these 6. Its average build year of 1974 against a peer-group mean of 1978 is in line with the group.

Showing the 5 closest of 82 Michigan counties eligible for comparison.

Bridge inventory size and condition shares for Delta County and the 5 Michigan counties closest to it in inventory size
County Bridges Poor
Clare County 96 3.1%
Menominee County 96 9.4%
Delta County (this page) 84 1.2%
Arenac County 80 18.8%
Mecosta County 80 5%
Cheboygan County 73 19.2%

Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Delta County's. Source: FHWA National Bridge Inventory, 2024 release.

Nationwide counties with similar inventory size or average build year

Two NBI-derived peer sets for Delta County, both outside Michigan so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside MI (84 bridges here).

Similar average build year

Nearest mean year-built outside MI (1974 here).

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 84 Good 32 Fair 51 Poor 1

All bridges (84)

COUNTY ROAD G 16

Fair

Over: TACOOSH RIVER

2 MI S E OF PERKINS, Delta, MI

Built 1972 Load: 97.2 t ADT: 46

ROUTE 442 FH76

Good

Over: STURGEON RIVER

14 MI N OF NAHMA JCT, Delta, MI

Built 2004 Load: 21.4 t ADT: 105

ROUTE 537

Good

Over: TEN MILE CREEK

6.5 MI W OF ESCANABA, Delta, MI

Built 1977 Load: 27.2 t ADT: 278

ROUTE 434

Good

Over: DAY S RIVER

1.5 MI SW OF BRAMPTON, Delta, MI

Built 1959 Load: 29.3 t ADT: 148

US-2 US-41

Good

Over: ESCANABA RIVER

3.6 MI N OF ESCANABA, Delta, MI

Built 2019 Load: 32.4 t ADT: 26,050

AIRPORT ROAD

Good

Over: PORTAGE CREEK

DELTA CO AIRPORT, Delta, MI

Built 2004 Load: 33.0 t ADT: 474

COUNTY ROAD B 9

Good

Over: TEN MILE CREEK

8 MI W OF ESCANABA, Delta, MI

Built 2002 Load: 33.4 t ADT: 26

1ST AVE

Good

Over: WILLOW CREEK

0.1 MI N OF US-2/41, Delta, MI

Built 1992 Load: 33.4 t ADT: 1,000

COUNTY ROAD G 3

Good

Over: RAPID RIVER

8 M N 2 M W RAPID RIVER, Delta, MI

Built 1986 Load: 36.0 t ADT: 58

6TH AVENUE

Good

Over: WILLOW CREEK

ESCANABA, Delta, MI

Built 2007 Load: 37.3 t ADT: 7,500

WILLOW CREEK ROAD

Good

Over: WILLOW CREEK

0.5 MI S OF US-2/41, Delta, MI

Built 2003 Load: 37.5 t ADT: 3,100

M-35

Good

Over: DAYS RIVER

IN BRAMPTON, Delta, MI

Built 1966 Load: 37.9 t ADT: 3,875

ROUTE 513

Good

Over: SQUAW CREEK

9.1 MI S JCT US-2, Delta, MI

Built 2010 Load: 38.9 t ADT: 446

US-2 WB & US-41 SB

Good

Over: DAYS RIVER

3.5 MI N OF M-35, Delta, MI

Built 1971 Load: 39.2 t ADT: 4,267

ROUTE 523

Good

Over: HUNTERS# BROOK

4 MI N OF CORNELL, Delta, MI

Built 2001 Load: 40.1 t ADT: 270

US-2

Good

Over: OGONTZ RIVER

4.0 MI W NAHMA JUNCTION, Delta, MI

Built 2015 Load: 40.5 t ADT: 4,275

US-2

Good

Over: BULL RUN CREEK

1.3 MI E NAHMA JUNCTION, Delta, MI

Built 1936 Load: 41.5 t ADT: 3,462

ROUTE 430

Good

Over: DAYS RIVER

1.5 MI WEST OF M 35, Delta, MI

Built 2022 Load: 43.4 t ADT: 253

ROUTE 535

Good

Over: BARK RIVER

10 MI SW OF ESCANABA, Delta, MI

Built 1961 Load: 46.0 t ADT: 234

US-2

Good

Over: STURGEON RIVER

0.3 MI E NAHMA JUNCTION, Delta, MI

Built 1972 Load: 47.0 t ADT: 3,462

ROUTE 535

Good

Over: BARK RIVER

4.9 MI S E OF BARK RIVER, Delta, MI

Built 2006 Load: 47.1 t ADT: 378

ROUTE 430

Good

Over: ESCANABA RIVER

0.5 MI N OF CORNELL, Delta, MI

Built 1973 Load: 47.3 t ADT: 173

US-2 US-41

Good

Over: BARK RIVER

1.8 MI NE OF BARK RIVER, Delta, MI

Built 1931 Load: 47.6 t ADT: 7,896

COUNTY ROAD I 39

Good

Over: RAPID RIVER

6.5 M N 1 M W RAPID RIVER, Delta, MI

Built 2016 Load: 49.9 t ADT: 83

ROUTE 430

Good

Over: SQUAW CREEK

5.0 MI W OF BEAVER, Delta, MI

Built 2006 Load: 51.8 t ADT: 132

ROUTE 535

Good

Over: BARK RIVER

5.6 MI S E OF BARK RIVER, Delta, MI

Built 2006 Load: 53.6 t ADT: 378

RTE 535 (8TH RD)

Good

Over: BARK RIVER

BARK TWP SEC 28 - 33, Delta, MI

Built 2006 Load: 53.6 t ADT: 378

COUNTY ROAD I 18

Good

Over: RAPID RIVER

3 MI N OF RAPID RIVER, Delta, MI

Built 2014 Load: 58.6 t ADT: 158

COUNTY ROAD G 24

Good

Over: TACOOSH RIVER

2 M N 1 M E OF BRAMPTON, Delta, MI

Built 2014 Load: 61.6 t ADT: 125

COUNTY ROAD B 17

Good

Over: BARK RIVER

9 MI W OF ESCANABA, Delta, MI

Built 2016 Load: 61.9 t ADT: 30

COUNTY ROAD F 4

Good

Over: DAYS RIVER

1.5 M W 0.5 M N BRAMPTON, Delta, MI

Built 2015 Load: 70.6 t ADT: 88

COUNTY ROAD G 17

Good

Over: DAYS RIVER

2.5 M W 1.5 M S PERKINS, Delta, MI

Built 2018 Load: 71.6 t ADT: 26

COUNTY ROAD I 26

Good

Over: TACOOSH RIVER

.5 M W .5 M N RAPID RIVER, Delta, MI

Built 2017 Load: 97.2 t ADT: 78

ROUTE 410

Poor

Over: TEN MILE CREEK

11 MI W OF ESCANABA, Delta, MI

Built 1939 Load: 20.1 t ADT: 444

Read our methodology - how this data is sourced, computed, and verified.

Related

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Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges

Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.