County profile · official public datasets

Matanuska-Susitna County, AK

120 public highway bridges tracked in the FHWA National Bridge Inventory: 50.8% rated Good, 43.3% Fair, 5.8% Poor.

120
Public bridges: 50.8%
Good condition: 5.8%
Poor condition

The verdict

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

Matanuska-Susitna County posts a better-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

Top 33%
lowest Poor share in state: 5.8%
Poor-condition share: 120
public highway bridges: 1993
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.

Matanuska-Susitna County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Matanuska-Susitna County ranks #9 of 27 Alaska counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 5.8%). Matanuska-Susitna County, Alaska contains 120 public highway bridges. Roughly 50.8% are rated “Good,” 43.3% “Fair,” and 5.8% “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

120

Public highway bridges in Matanuska-Susitna County

Good condition

50.8%

61 of 120 rated 7-9

Fair condition

43.3%

52 of 120 rated 5-6

Poor condition

5.8%

7 of 120 rated 4 or below

In-state Poor-share rank

#9 of 27

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

Condition distribution

Share of 120 NBI-tracked bridges by lowest applicable component rating.

Good

50.8% (61)

Fair

43.3% (52)

Poor

5.8% (7)

Matanuska-Susitna County's Poor-condition bridges carry 2,950 vehicle crossings a day

That is 0.9% of the county's reported daily bridge traffic on 5.8% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 421 crossings a day against 3,373 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 120 of 120 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

25% of Matanuska-Susitna County's bridges have passed the 50-year mark

30 of the 120 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 50.8% 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 53.6% of the county's Poor-condition bridge traffic

GLENN HIGHWAY over KINGS RIVER, built 1961, carries 1,580 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 7-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 2,950 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1930s

2
1940s

1
1950s

5
1960s

11
1970s

14
1980s

9
1990s

18
2000s

31
2010s

26
2020s

3

What this shows Construction peaked in the 2000s, when 31 of the county's bridges still in the inventory were built, which is 25.8% of those with a recorded year. That cohort is now 15 to 24 years old in the 2024 inventory. Its average build year (1993) matches the Alaska average (1989).

How Matanuska-Susitna County compares with Alaska's closest counties by inventory size

The 5 Alaska counties nearest Matanuska-Susitna County in number of bridges, with their condition splits. Its 5.8% Poor share is the 2nd-lowest of these 6. Its average build year of 1993 against a peer-group mean of 1991 is in line with the group.

Showing the 5 closest of 26 Alaska counties eligible for comparison.

Bridge inventory size and condition shares for Matanuska-Susitna County and the 5 Alaska counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Anchorage County	134	49.3%	50%	0.7%	1992
Hoonah-Angoon County	125	49.6%	35.2%	15.2%	1994
Matanuska-Susitna County (this page)	120	50.8%	43.3%	5.8%	1993
Fairbanks North Star County	111	50.5%	42.3%	7.2%	1988
Kenai Peninsula County	103	35.9%	50.5%	13.6%	1988
Ketchikan Gateway County	100	43%	45%	12%	1993

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 Matanuska-Susitna 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 Matanuska-Susitna County, both outside Alaska so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside AK (120 bridges here).

Indian River County, FL · 120 bridges
Perry County, MO · 120 bridges
Schuyler County, MO · 120 bridges
Sanders County, MT · 120 bridges

Similar average build year

Nearest mean year-built outside AK (1993 here).

Salt Lake County, UT · avg 1993 · 659 bridges
Marshall County, MS · avg 1993 · 255 bridges
Rowan County, NC · avg 1993 · 245 bridges
Cabarrus County, NC · avg 1993 · 236 bridges

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

All 120 Good 61 Fair 52 Poor 7

All bridges (120)

Sort:

Matanuska-Susitna County Bridge Snapshot

Condition distribution

Matanuska-Susitna County's Poor-condition bridges carry 2,950 vehicle crossings a day

25% of Matanuska-Susitna County's bridges have passed the 50-year mark

One structure carries 53.6% of the county's Poor-condition bridge traffic

How Matanuska-Susitna County compares with Alaska's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

All bridges (120)

COLLINSVILLE TRAIL

LEWIS PARKWAY ROAD

DENALI HIGHWAY

GLENN HIGHWAY

GLENN HIGHWAY

DENALI HIGHWAY

BIG LAKE ROAD

PETERSVILLE ROAD

PARKS HIGHWAY

PARKS HIGHWAY

YODER ROAD

PARKS HIGHWAY

SHIRLEY TOWNE DR

PARKS HIGHWAY

WILLOW/FISHHOOK RD

BRADLEY ROAD

N SUSHANA ST

PALMER-WASILL EXT

PARKS HIGHWAY

OLD GLENN PALMER

ELK ROAD

BACK ACRES ROAD

PARKS HIGHWAY

OLD GLENN PALMER

MIDNIGHT DRIVE

PARKS HIGHWAY

PARKS HIGHWAY

KNIK RIVER ROAD

PARKS HIGHWAY

PARKS HIGHWAY

PARKS HIGHWAY

GLENN HIGHWAY

DENALI HIGHWAY

PARKS HIGHWAY

FERN MINE ROAD

GLENN HIGHWAY

SCHROCK RD SPUR

PARKS HIGHWAY

EDGERTON PARKS RD

GLENN HIGHWAY

IRR:CHICKALOON FRK

SNOWBALL COURT

PARKS HIGHWAY

PARKS HIGHWAY

GLENN HIGHWAY

PETERSVILLE ROAD

WOLVERINE ROAD

GLENN HIGHWAY

PLUMLEY ROAD

PALMER/WASILLA HWY

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