County profile · official public datasets

Millard County, UT

72 public highway bridges tracked in the FHWA National Bridge Inventory: 12.5% rated Good, 86.1% Fair, 1.4% Poor.

72
Public bridges: 12.5%
Good condition: 1.4%
Poor condition

The verdict

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

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

Top 41%
lowest Poor share in state: 1.4%
Poor-condition share: 72
public highway bridges: 1978
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.

Millard County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Millard County ranks #12 of 29 Utah counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 1.4%). Millard County, Utah contains 72 public highway bridges. Roughly 12.5% are rated “Good,” 86.1% “Fair,” and 1.4% “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

Public highway bridges in Millard County

Good condition

12.5%

9 of 72 rated 7-9

Fair condition

86.1%

62 of 72 rated 5-6

Poor condition

1.4%

1 of 72 rated 4 or below

In-state Poor-share rank

#12 of 29

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

Condition distribution

Share of 72 NBI-tracked bridges by lowest applicable component rating.

Good

12.5% (9)

Fair

86.1% (62)

Poor

1.4% (1)

Millard County's Poor-condition bridges carry 38 vehicle crossings a day

That is 0% of the county's reported daily bridge traffic on 1.4% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 38 crossings a day against 3,923 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 71 of 72 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

54.2% of Millard County's bridges have passed the 50-year mark

39 of the 72 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 12.5% 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

COUNTY ROAD over CENTRAL UTAH CANAL, built 1935, carries 38 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 38 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1930s

2
1950s

3
1960s

9
1970s

37
1980s

10
1990s

4
2000s

2
2010s

2
2020s

3

What this shows Construction peaked in the 1970s, when 37 of the county's bridges still in the inventory were built, which is 51.4% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year is 1978, 6 years older than the Utah average of 1984.

How Millard County compares with Utah's closest counties by inventory size

The 5 Utah counties nearest Millard County in number of bridges, with their condition splits. Its 1.4% Poor share is the 1st-lowest of these 6. Its average build year of 1978 against a peer-group mean of 1981 is in line with the group.

Showing the 5 closest of 28 Utah counties eligible for comparison.

Bridge inventory size and condition shares for Millard County and the 5 Utah counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Uintah County	91	31.9%	64.8%	3.3%	1989
Duchesne County	84	26.2%	67.9%	6%	1984
Carbon County	73	19.2%	78.1%	2.7%	1974
Millard County (this page)	72	12.5%	86.1%	1.4%	1978
Iron County	70	10%	88.6%	1.4%	1977
Juab County	60	8.3%	88.3%	3.3%	1980

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

Similar inventory size

Nearest county inventories outside UT (72 bridges here).

Lafayette County, AR · 72 bridges
Tattnall County, GA · 72 bridges
Wilkinson County, GA · 72 bridges
Kearny County, KS · 72 bridges

Similar average build year

Nearest mean year-built outside UT (1978 here).

Orange County, CA · avg 1978 · 1,164 bridges
Sumner County, KS · avg 1978 · 659 bridges
Allen County, IN · avg 1978 · 613 bridges
Livingston County, IL · avg 1978 · 579 bridges

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

All 72 Good 9 Fair 62 Poor 1

All bridges (72)

Sort:

Millard County Bridge Snapshot

Condition distribution

Millard County's Poor-condition bridges carry 38 vehicle crossings a day

54.2% of Millard County's bridges have passed the 50-year mark

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

How Millard County compares with Utah'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 (72)

I-15 (SR-15) NBL

I-15 (SR-15) NBL

I-15 (SR-15) SBL

SR-161 INT.X-RD

CHALK CREEK ROAD

200 SO.ST.-HOLDEN

CHALK CREEK ROAD

ROAD

COUNTY ROAD

I-70EB (SR-70)

I-15 (SR-15) SBL

I-70 (SR-70) WBL

2500 SOUTH ROAD-CO

SR-99

I-15 (SR-15) NBL

I-15 (SR-15) NBL

I-15 (SR-15) SBL

I-15 (SR-15) SBL

CNTY.ROAD FA.#1948

CO.RD. INT.X-ROAD.

I-70 (SR-70) EBL

I-70 (SR-70) WBL

HORSE HOLLOW TRAIL

SR-64 INT.X-RD.

I-70 (SR-70) WBL

I-15 (SR-15) NBL

I-15 (SR-15) SBL

US-6 (SR-6)

I-15 (SR-15) SBL

CO. RD. AT HATTON

US-50 (SR-50)

1500 N. COUNTY RD.

200 SOUTH STREET

COUNTY ROAD

US-6 (SR-6)

I-15 (SR-15) NBL

4000 WEST

4000 W. COUNTY RD.

CNTY.ROAD FA.#1948

SR-100

I-15 (SR-15)NB&SB

I-15 (SR-15) NBL

SR-99 INT.X-RD.

CO.RD.SO.OF MEADOW

I-15 (SR-15)NB&SB

I-15 (SR-15)NB&SB

SR-125

I-15 (SR-15)NB&SB

US-50 (SR-50)

US-6 (SR-6)

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