County profile · official public datasets

Grant County, WA

306 public highway bridges tracked in the FHWA National Bridge Inventory: 63.7% rated Good, 33.7% Fair, 2.6% Poor.

306
Public bridges
63.7%
Good condition
2.6%
Poor condition

The verdict

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

Grant County posts a top-quartile lowest Poor-condition share among rated counties in the state across mid-size county bridge inventory.

Top 15%
lowest Poor share in state
2.6%
Poor-condition share
306
public highway bridges
1973
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.

Grant County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Grant County ranks #6 of 39 Washington counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 2.6%). Grant County, Washington contains 306 public highway bridges. Roughly 63.7% are rated “Good,” 33.7% “Fair,” and 2.6% “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

306

Public highway bridges in Grant County

Good condition

63.7%

195 of 306 rated 7-9

Fair condition

33.7%

103 of 306 rated 5-6

Poor condition

2.6%

8 of 306 rated 4 or below

In-state Poor-share rank

#6 of 39

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

Condition distribution

Share of 306 NBI-tracked bridges by lowest applicable component rating.

Good
63.7% (195)
Fair
33.7% (103)
Poor
2.6% (8)

Grant County's Poor-condition bridges carry 20,503 vehicle crossings a day

That is 4.4% of the county's reported daily bridge traffic on 2.6% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 2,563 crossings a day against 957 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 306 of 306 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

56.5% of Grant County's bridges have passed the 50-year mark

173 of the 306 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 63.7% 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 26.4% of the county's Poor-condition bridge traffic

I-90 over WEST CANAL, built 1964, carries 5,419 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 8-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 20,503 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Grant County's bridges were built

306 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1950s, when 90 of the county's bridges still in the inventory were built, which is 29.4% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year (1973) matches the Washington average (1975).

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

How Grant County compares with Washington's closest counties by inventory size

The 5 Washington counties nearest Grant County in number of bridges, with their condition splits. Its 2.6% Poor share is the 2nd-lowest of these 6. Its average build year of 1973 against a peer-group mean of 1973 is in line with the group.

Showing the 5 closest of 38 Washington counties eligible for comparison.

Bridge inventory size and condition shares for Grant County and the 5 Washington counties closest to it in inventory size
County Bridges Poor
Whatcom County 354 5.4%
Whitman County 347 3.5%
Kittitas County 308 10.4%
Spokane County 307 6.8%
Grant County (this page) 306 2.6%
Skagit County 254 2.4%

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

Similar inventory size

Nearest county inventories outside WA (306 bridges here).

Similar average build year

Nearest mean year-built outside WA (1973 here).

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

All 306 Good 195 Fair 103 Poor 8

All bridges (306)

Q SW

Good

Over: WEST CANAL BLK 78

Q SW .1 South of 1.5, Grant, WA

Built 1993 Load: 23.7 t ADT: 877

FRENCHMAN HILLS RD

Good

Over: WEST CANAL TUNNEL WW

Frenchmen Hill 1.2 E of I, Grant, WA

Built 1962 Load: 24.3 t ADT: 368

5 RD SE

Good

Over: IRRIGATION WASTEWAY

5 SE .4 West of M SE, Grant, WA

Built 1987 Load: 24.3 t ADT: 203

M NE

Good

Over: EAST LOW CANAL BLK 40

M NE 0.2 South of 10 NE, Grant, WA

Built 1996 Load: 24.3 t ADT: 443

FEISS RD

Good

Over: CON NA WAI CREEK

Fiess Rd 0.01 W of X NE, Grant, WA

Built 2000 Load: 24.3 t ADT: 56

SR 17

Good

Over: PARKER HORN

0.3 N JCT SR 171, Grant, WA

Built 1955 Load: 24.5 t ADT: 19,362

N RD SW

Good

Over: IRRIGATION LATERAL

N SW @ 12.5, Grant, WA

Built 1958 Load: 24.5 t ADT: 74

SR 281

Good

Over: WEST CANAL

9.9 N JCT I-90, Grant, WA

Built 1950 Load: 24.6 t ADT: 8,193

White Trail Rd

Good

Over: WINCHESTER WW

5 NW 0.05 W of G.9, Grant, WA

Built 1953 Load: 24.6 t ADT: 558

A NE

Good

Over: WEST CANAL BLK 70

A NE 1.23 N of SR 28, Grant, WA

Built 1988 Load: 24.6 t ADT: 226

G RD SW

Good

Over: WAHLUKE BRANCH CANAL

G SW .4 N of Wahluke Rd, Grant, WA

Built 1969 Load: 24.6 t ADT: 772

L ROAD SW

Good

Over: LAT. RB5 BLK 82

Adams Rd 0.9 S of 12 SW, Grant, WA

Built 1990 Load: 24.6 t ADT: 875

D Road SE

Good

Over: Irrigation Canal

D SE .9 mile S of 13 SE, Grant, WA

Built 2009 Load: 24.6 t ADT: 391

U ROAD SE

Good

Over: S. WARDEN COULEE

U SE .6 S of 10 SE, Grant, WA

Built 1960 Load: 24.9 t ADT: 1,373

K NE

Good

Over: ROCKY COULEE WW

K NE 1.8 South of 7 NE, Grant, WA

Built 1984 Load: 25.3 t ADT: 1,320

PINTO RIDGE ROAD

Good

Over: MAIN CANAL

Pinto Ridge .5 N of SR 28, Grant, WA

Built 1992 Load: 25.3 t ADT: 530

29 NE

Good

Over: WILSON CREEK

29 NE 4.02 East of R NE, Grant, WA

Built 1998 Load: 25.3 t ADT: 24

E RD SE

Good

Over: IRRIGATION LATERAL

E SE at 14.8, Grant, WA

Built 1959 Load: 25.4 t ADT: 80

D RD SW

Good

Over: IRRIGATION LATERAL

D SW 0.7 S of Frenchmen, Grant, WA

Built 1959 Load: 25.4 t ADT: 214

9 RD NW

Good

Over: IRRIGATION LATERAL

9 NW 0.3 E of S NW, Grant, WA

Built 1952 Load: 25.4 t ADT: 265

A RD SW

Good

Over: IRRIGATION LATERAL

A SW 0.5 N of 11 SW, Grant, WA

Built 1954 Load: 25.4 t ADT: 264

1 SE RD

Good

Over: ROCKY COULEE DRAIN

1 SE 0.8 West of M SE, Grant, WA

Built 2000 Load: 25.6 t ADT: 292

P RD NE

Good

Over: ROCKY COULEE

P NE 0.6 N of 6 NE, Grant, WA

Built 1974 Load: 25.9 t ADT: 160

SR 155

Good

Over: UPPER LEWIS CR

14.4 N JCT US 2, Grant, WA

Built 1949 Load: 26.6 t ADT: 959

F RD NW

Good

Over: WEST CANAL

F NW .8 S Martin Rd, Grant, WA

Built 1953 Load: 26.6 t ADT: 59

BEVERLY BURKE RD

Good

Over: WEST CANAL BLK 77

BEVERLY BURKE @ 1 NW, Grant, WA

Built 1987 Load: 26.6 t ADT: 1,452

J RD NE

Good

Over: MAIN CANAL

J NE 0.5 N of SR 28, Grant, WA

Built 1992 Load: 26.9 t ADT: 175

M Road SE

Good

Over: WW RCD BLK 42

M SE .5 South of 2 SE, Grant, WA

Built 1996 Load: 26.9 t ADT: 1,109

S RD SE

Good

Over: IRRIGATION LATERAL

S SE 0.4 S of SR 170, Grant, WA

Built 1952 Load: 27.2 t ADT: 196

N ROAD NE

Good

Over: LAT. BLK 41

N NE .5 North of I-90, Grant, WA

Built 1960 Load: 27.5 t ADT: 910

11 ROAD SW

Good

Over: ROYAL BRANCH CANAL BLK82

11 SW 0.7 E of K SW, Grant, WA

Built 1987 Load: 27.5 t ADT: 600

R NE

Good

Over: DRY CREEK

R NE .2 South of 39 NE, Grant, WA

Built 1994 Load: 27.5 t ADT: 250

T RD SE

Good

Over: EAST LOW CANAL

T SE .2 North of 7 SE, Grant, WA

Built 1984 Load: 27.9 t ADT: 49

L ROAD NE

Good

Over: ROCKY COULEE WW BLK 41

L NE .05 North of 5.6 NE, Grant, WA

Built 1983 Load: 27.9 t ADT: 1,271

SO. FRONTAGE RD

Good

Over: WEBER COULEE

S Frontage 2.9 E of U SE, Grant, WA

Built 1938 Load: 28.2 t ADT: 94

1 RD SE

Good

Over: WEBER WASTEWAY

1 SE 0.2 West of S SE, Grant, WA

Built 1950 Load: 28.2 t ADT: 156

O RD NE

Good

Over: LATERAL W 1150

O NE .5 South of 3 NE, Grant, WA

Built 1987 Load: 28.2 t ADT: 593

7 NW

Good

Over: West Canal

7 NW 0.1 West of R NW, Grant, WA

Built 2004 Load: 28.2 t ADT: 680

8 ROAD SE

Good

Over: EAST LOW CANAL BLK 44

8 SE 0.6 W of W SE, Grant, WA

Built 1985 Load: 28.8 t ADT: 719

4 RD SE

Good

Over: WASTEWAY

4 SE 0.4 West of M SE, Grant, WA

Built 1987 Load: 28.8 t ADT: 138

E RD SW

Good

Over: WAHLUKE BRANCH CANAL

E SW .6 N of Wahlike Rd, Grant, WA

Built 1969 Load: 28.8 t ADT: 303

M NW

Good

Over: West Canal

M NW 0.2 S of 11, Grant, WA

Built 2004 Load: 28.8 t ADT: 560

3 RD SE

Good

Over: WASTEWAY

3 SE .5 West of M SE, Grant, WA

Built 1987 Load: 29.2 t ADT: 78

BASELINE WEST

Good

Over: LAT. BLK 73

Baseline .1 East of V NW, Grant, WA

Built 1987 Load: 29.8 t ADT: 650

MAINTENANCE ROAD

Good

Over: WEST CANAL

DRY COULEE SIPHON 1 OUTLE, Grant, WA

Built 1946 Load: 29.9 t ADT: 5

MAINTENANCE ROAD

Good

Over: WEST CANAL

Dry Coulee Siphon 2 Outle, Grant, WA

Built 1946 Load: 29.9 t ADT: 5

SR 28

Good

Over: WINCHESTER WASTEWAY

8.4 E JCT SR 281, Grant, WA

Built 1949 Load: 30.1 t ADT: 5,489

M.5 RD SW

Good

Over: SADDLE MOUNTAIN WW

M.5 0.1 S of 24 SW, Grant, WA

Built 1974 Load: 30.1 t ADT: 50

C RD SE

Good

Over: WEST CANAL

C SE .7 N of 12, Grant, WA

Built 1964 Load: 30.1 t ADT: 139

K RD SW

Good

Over: WAHLUKE BRANCH CANAL

K SW .4 N of 22.5, Grant, WA

Built 1969 Load: 30.5 t ADT: 229

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.