County profile · official public datasets

Martin County, MN

162 public highway bridges tracked in the FHWA National Bridge Inventory: 56.2% rated Good, 34.6% Fair, 9.3% Poor.

162
Public bridges: 56.2%
Good condition: 9.3%
Poor condition

The verdict

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

Martin County pairs a higher-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.

83rd
of 87 on Poor share: 9.3%
Poor-condition share: 162
public highway bridges: 1975
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.

Martin County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Martin County ranks #83 of 87 Minnesota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 9.3%). Martin County, Minnesota contains 162 public highway bridges. Roughly 56.2% are rated “Good,” 34.6% “Fair,” and 9.3% “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

162

Public highway bridges in Martin County

Good condition

56.2%

91 of 162 rated 7-9

Fair condition

34.6%

56 of 162 rated 5-6

Poor condition

9.3%

15 of 162 rated 4 or below

In-state Poor-share rank

#83 of 87

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

Condition distribution

Share of 162 NBI-tracked bridges by lowest applicable component rating.

Good

56.2% (91)

Fair

34.6% (56)

Poor

9.3% (15)

Martin County's Poor-condition bridges carry 2,560 vehicle crossings a day

That is 1.3% of the county's reported daily bridge traffic on 9.3% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 171 crossings a day against 911 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 162 of 162 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

46.9% of Martin County's bridges have passed the 50-year mark

76 of the 162 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 56.2% 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 42.5% of the county's Poor-condition bridge traffic

CSAH 53 over CENTER CREEK, built 1930, carries 1,089 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 15-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 2,560 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

8
1920s

4
1930s

3
1940s

4
1950s

5
1960s

10
1970s

78
1980s

13
1990s

13
2000s

13
2010s

6
2020s

5

What this shows Construction peaked in the 1970s, when 78 of the county's bridges still in the inventory were built, which is 48.1% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year is 1975, 11 years older than the Minnesota average of 1986.

How Martin County compares with Minnesota's closest counties by inventory size

The 5 Minnesota counties nearest Martin County in number of bridges, with their condition splits. Its 9.3% Poor share is the 6th-lowest of these 6. Its average build year of 1975 against a peer-group mean of 1985 is 10 years older.

Showing the 5 closest of 86 Minnesota counties eligible for comparison.

Bridge inventory size and condition shares for Martin County and the 5 Minnesota counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Pine County	171	63.2%	32.2%	4.7%	1987
Itasca County	170	50%	44.7%	5.3%	1985
Watonwan County	167	69.5%	29.9%	0.6%	1978
Morrison County	164	62.2%	33.5%	4.3%	1988
Martin County (this page)	162	56.2%	34.6%	9.3%	1975
Kittson County	160	71.9%	25.6%	2.5%	1988

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 Martin 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 Martin County, both outside Minnesota so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside MN (162 bridges here).

Perry County, AL · 162 bridges
Johnson County, AR · 162 bridges
Ouachita County, AR · 162 bridges
Bond County, IL · 162 bridges

Similar average build year

Nearest mean year-built outside MN (1975 here).

San Bernardino County, CA · avg 1975 · 1,422 bridges
Lane County, OR · avg 1975 · 1,010 bridges
Fulton County, GA · avg 1975 · 775 bridges
Westmoreland County, PA · avg 1975 · 620 bridges

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

All 162 Good 91 Fair 56 Poor 15

Good-condition bridges (91)

Sort:

Martin County Bridge Snapshot

Condition distribution

Martin County's Poor-condition bridges carry 2,560 vehicle crossings a day

46.9% of Martin County's bridges have passed the 50-year mark

One structure carries 42.5% of the county's Poor-condition bridge traffic

How Martin County compares with Minnesota's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

Good-condition bridges (91)

CSAH 39

T 2

T 109

MSAS 111

T 49

T 135

MN 263

I 90

I 90

I 90

MSAS 120

CR 107

T 67

T 20

T 206

T 22

T 101

T 72

T 70

CSAH 26

T 300

T 16

T 291

CSAH 12

T 298

CSAH 44

MN 4

T 69

T 205

CSAH 18

T 174

MN 4

CSAH 36

MSAS 101

T 75

CR 107

T 31

T 22

CSAH 32

T 75

CSAH 59

Related