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

72

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.

When Millard County's bridges were built

72 bridges with a recorded construction year, grouped by decade

bridges

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.

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

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 Poor
Uintah County 91 3.3%
Duchesne County 84 6%
Carbon County 73 2.7%
Millard County (this page) 72 1.4%
Iron County 70 1.4%
Juab County 60 3.3%

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).

Similar average build year

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

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)

US-6 (SR-6)

Fair

Over: SEVIER RIVER

3.0 Miles West of Delta, Millard, UT

Built 2005 Load: 41.5 t ADT: 3,910

SR-132

Fair

Over: SEVIER RIVER

2.8 MILES EAST OF LYNNDYL, Millard, UT

Built 1958 Load: 42.1 t ADT: 1,684

COUNTY ROAD

Fair

Over: SEVIER RIVER

1 MILE SOUTH OF LYNNDYL, Millard, UT

Built 1976 Load: 44.4 t ADT: 38

I-15 (SR-15) SBL

Fair

Over: DEER CROSSING

1 MILE SOUTH OF SCIPIO, Millard, UT

Built 1978 Load: 44.4 t ADT: 19,660

SR-257

Fair

Over: SEVIER RIVER

IN TOWN OF DESERET, Millard, UT

Built 1985 Load: 45.4 t ADT: 1,704

I-15 (SR-15) NBL

Fair

Over: DEER CROSSING

1 MILE SOUTH OF SCIPIO, Millard, UT

Built 1978 Load: 46.3 t ADT: 19,660

I-15 (SR-15)NB&SB

Fair

Over: SCIPIO VALLEY DRAINAGE

0.2 MILES SOUTH OF SCIPIO, Millard, UT

Built 1978 Load: 47.3 t ADT: 19,660

WILD GOOSE RD.-CO.

Fair

Over: I-15 (SR-15) NBL & S

2.3 NO.OF SO. HOLDEN INT., Millard, UT

Built 1976 Load: 47.6 t ADT: 500

SR-100

Fair

Over: CHALK CREEK

50 WEST 400 NO. FILLMORE, Millard, UT

Built 1988 Load: 65.1 t ADT: 1,289

I-15 SB

Fair

Over: Wildlife Crossing

I-15 over Wildlife Cross., Millard, UT

Built 2021 Load: 90.7 t ADT: 20,000

I-15 NB

Fair

Over: Wildlife Crossing

I-15 over Wildlife Cross., Millard, UT

Built 2021 Load: 94.0 t ADT: 20,000

2000 W. ROAD-CO

Fair

Over: WOODROW CANAL

2400 N.2000 W.DELTA AREA, Millard, UT

Built 1985 Load: 96.6 t ADT: 50

COUNTY ROAD

Good

Over: CENTRAL UTAH CANAL

1 MILE SE. OF LEAMINGTON, Millard, UT

Built 1996 Load: 18.1 t ADT: 38

3000 W. COUNTY RD

Good

Over: ABRAHAM CANAL

50 S. 3000 W. DELTA, Millard, UT

Built 1993 Load: 32.7 t ADT: 252

COUNTY ROAD

Good

Over: SCIPIO LAKE DAM SPILLWAY

WEST END OF SCIPIO LK.DAM, Millard, UT

Built 1989 Load: 33.7 t ADT: 13

I-15 SB

Good

Over: Dog Valley Access Rd

I-15 SB over Dog Valley, Millard, UT

Built 2022 Load: 35.6 t ADT: 23,000

COUNTY ROAD

Good

Over: SEVIER RIVER

NORTH SIDE OF LEAMINGTON, Millard, UT

Built 1996 Load: 37.9 t ADT: 38

US-6 (SR-6)

Good

Over: DESERET CANAL

3.3 Miles West of Delta, Millard, UT

Built 2005 Load: 38.9 t ADT: 3,910

COUNTY ROAD

Good

Over: D.M.A.D. RESERVOIR CANAL

50 W.SHEPARD LN. (750 N.), Millard, UT

Built 1996 Load: 46.0 t ADT: 252

I-70 (SR-70) EBL

Good

Over: I-15 (SR-15) NBL AND SBL

COVE FORT INTERCHANGE, Millard, UT

Built 1966 Load: 51.5 t ADT: 7,577

SR-21

Good

Over: TUNNEL SPRING MTNS. WASH

28 MILES SE.OF GARRISON, Millard, UT

Built 1975 Load: 96.6 t ADT: 231

COUNTY ROAD

Poor

Over: CENTRAL UTAH CANAL

2 MILES SW. OF LEAMINGTON, Millard, UT

Built 1935 Load: 1.3 t ADT: 38

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.