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

Good-condition bridges (195)

Martin Rd

Good

Over: Lateral Canal

Martin Rd @ H-NW, Grant, WA

Built 2015 Load: 7.8 t ADT: 443

Farm Access

Good

Over: West Canal W27 Lateral

West Canal W27 Lateral St, Grant, WA

Built 1998 Load: 9.3 t ADT: 5

SR 174

Good

Over: COLUMBIA BASIN CANAL

1.3 E DOUGLAS CO, Grant, WA

Built 1949 Load: 12.6 t ADT: 1,437

G RD NW

Good

Over: WEST CANAL

G NW 0.2 N of SR 28, Grant, WA

Built 1977 Load: 14.6 t ADT: 50

U ROAD SE

Good

Over: WEBER COULEE

U SE at 1 SE, Grant, WA

Built 1954 Load: 16.5 t ADT: 1,086

U ROAD SE

Good

Over: LIND COULEE

U SE .7 South of 4, Grant, WA

Built 1954 Load: 16.5 t ADT: 1,136

SR 283

Good

Over: WINCHESTER WASTEWAY

9.2 N JCT SR 281, Grant, WA

Built 1953 Load: 16.8 t ADT: 2,499

11 & V NE

Good

Over: FIELD RUNOFF

11 & V NE, Grant, WA

Built 1978 Load: 16.8 t ADT: 10

DODSON RD

Good

Over: LAT W20F BLK 89

Dodson 0.7 South of 7 NW, Grant, WA

Built 1993 Load: 17.5 t ADT: 1,489

O-SW

Good

Over: WEST LOW CANAL

O SW .06 N of Frenchmen, Grant, WA

Built 1997 Load: 17.8 t ADT: 155

E ROAD SW

Good

Over: Crab Creek

E SW at Crab Creek, Grant, WA

Built 1958 Load: 18.1 t ADT: 233

LOWER CRAB CR RD

Good

Over: LOWER CRAB CREEK

LWR Crab CR 5.2 E SR 243, Grant, WA

Built 1979 Load: 18.1 t ADT: 50

E RD SE

Good

Over: WEST CANAL

E SE .4 N of 12, Grant, WA

Built 1960 Load: 18.1 t ADT: 550

MAINTENANCE ROAD

Good

Over: WEST CANAL

WEST CANAL, Grant, WA

Built 1956 Load: 18.3 t ADT: 30

6 RD SE

Good

Over: LIND COULEE WASTEWAY

6 SE 1.8 East of U SE, Grant, WA

Built 1991 Load: 19.1 t ADT: 260

6 ROAD NE

Good

Over: EAST LOW CANAL BLK 41

6 NE 0.9 East of N NE, Grant, WA

Built 1989 Load: 19.1 t ADT: 215

7 ROAD NE

Good

Over: CRAB CREEK

7 NE .5 E of Stratford Rd, Grant, WA

Built 1952 Load: 19.1 t ADT: 2,068

K RD NW

Good

Over: LAT. BL 73

K NW 0.2 North of SR 28, Grant, WA

Built 1999 Load: 19.1 t ADT: 184

8 ROAD SE

Good

Over: LIND COULEE WASTEWAY

8 SE .2 East of W SE, Grant, WA

Built 1988 Load: 19.4 t ADT: 212

R RD NW

Good

Over: LAT. BLK 73

13 th Avenue N, Grant, WA

Built 1995 Load: 19.4 t ADT: 385

P NW

Good

Over: CANAL W26A BLK 73

P NW .4 N of 11 NW, Grant, WA

Built 1993 Load: 19.4 t ADT: 546

Road 14.3 NW

Good

Over: WEST CANAL

14.3 NW 0.1 W of SR 28, Grant, WA

Built 1999 Load: 19.4 t ADT: 65

WHITE TRAIL

Good

Over: LAT 39.9 BLK 75

5 NW @ R NW, Grant, WA

Built 1994 Load: 20.1 t ADT: 5,333

RIDGEVIEW RD

Good

Over: WASTEWAY

Ridgeview .02 W of L NE, Grant, WA

Built 1994 Load: 20.1 t ADT: 465

FARM ACCESS

Good

Over: WEST CANAL LATERAL W26C

WEST CANAL LATERAL W26C, Grant, WA

Built 2015 Load: 20.3 t ADT: 20

DODSON ROAD

Good

Over: WEST CANAL BLK 86

Dodson Rd .4 N of 11 SW, Grant, WA

Built 1993 Load: 20.4 t ADT: 2,266

SAND DUNE ROAD

Good

Over: MOSES LAKE SPILLWAY

MOSES LAKE SPILLWAY, Grant, WA

Built 1962 Load: 20.7 t ADT: 50

HILL TOP RD

Good

Over: FRENCHMAN SPRINGS

Vantage Rd 1.0 W Silica, Grant, WA

Built 1931 Load: 20.7 t ADT: 169

Farm Access

Good

Over: West Canal W26C Lateral

West Canal W26C Lateral, Grant, WA

Built 2007 Load: 20.8 t ADT: 20

19 NW

Good

Over: WEST CANAL

19 NW .6 W of B, Grant, WA

Built 1994 Load: 21.4 t ADT: 240

BASELINE EAST

Good

Over: WASTEWAY

Baseline 0.2 W of SR 17, Grant, WA

Built 1996 Load: 21.4 t ADT: 1,296

SR 28

Good

Over: WEST CANAL

0.9 E JCT SR 281, Grant, WA

Built 1950 Load: 21.7 t ADT: 7,985

3 RD NW

Good

Over: IRRIGATION LATERAL

3 NW 0.03 East of SR 281, Grant, WA

Built 1952 Load: 21.8 t ADT: 110

MAINTENANCE ROAD

Good

Over: WEST CANAL W39.9

West Canal W39.9 Station, Grant, WA

Built 1950 Load: 22.1 t ADT: 40

23 ROAD NE

Good

Over: CRAB CREEK

01.6 E SR 28, Grant, WA

Built 1990 Load: 22.7 t ADT: 467

T RD NW

Good

Over: IRRIGATION LATERAL

T NW .5 N of 12, Grant, WA

Built 1952 Load: 22.7 t ADT: 197

SR 17

Good

Over: CANAL

8.3 N JCT SR 170, Grant, WA

Built 1954 Load: 23.0 t ADT: 8,845

FRENCHMAN HILLS RD

Good

Over: WEST CANAL

Frenchmen .2 E of Adams, Grant, WA

Built 1987 Load: 23.0 t ADT: 557

MAPLE STREET

Good

Over: WILSON CREEK

.1 MI E OF FOURTH, Grant, WA

Built 1979 Load: 23.0 t ADT: 30

GEORGE SOUTH ROAD

Good

Over: WEST CANAL BLK 78

Q SW 1.3 South of 3, Grant, WA

Built 1993 Load: 23.3 t ADT: 831

M Road SE

Good

Over: WW RCD BLK 42

M SE 0.1 S of 5.5 SE, Grant, WA

Built 1996 Load: 23.3 t ADT: 1,184

SPILLWAY ACCESS

Good

Over: WINCHESTER WASTEWAY

NR WINCHESTER WA, Grant, WA

Built 1948 Load: 23.7 t ADT: 5

SR 155

Good

Over: NORTHRUP CR

19.1 N JCT US 2, Grant, WA

Built 1949 Load: 23.7 t ADT: 1,142

DODSON ROAD

Good

Over: CANAL LATERAL

Dodson 1.3 N of 9 NW, Grant, WA

Built 1981 Load: 23.7 t ADT: 1,567

L ROAD SW

Good

Over: LAT. W61C BLK 81

Adams .4 South of 9 SW, Grant, WA

Built 1964 Load: 23.7 t ADT: 1,412

ADAMS ROAD

Good

Over: WEST CANAL BLK 78

Adams .1 N of Frenchmen, Grant, WA

Built 1994 Load: 23.7 t ADT: 1,237

12 RD NW

Good

Over: WEST CANAL

Martin Rd 0.1 W of SR 28, Grant, WA

Built 1994 Load: 23.7 t ADT: 825

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

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.