Thurston County Bridge Report Card

Thurston County scores 84 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

B84 / 100

Local infrastructure snapshot

Thurston County, Washington

Thurston County has 199 bridges in the National Bridge Inventory, with 2 rated poor and 13 rated scour-critical. Its poor-condition share of 1.0% is at or below the 5.6% statewide average. Poor-condition bridges carry about 20,643 daily vehicle crossings.

199Total Bridges

2Poor (1.0%)

79Fair (39.7%)

13Scour-Critical

Quote-Ready Local Facts

1.0%of county bridges are in poor condition, compared with 5.6% statewide and 6.7% nationally.

20,643daily vehicle crossings are on poor-condition bridges in the county.

13bridges are rated scour-critical, or 6.5% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Thurston County a Bridge Condition Exposure Score of 84/100 (B). The county has 199 bridges in the National Bridge Inventory, including 2 in poor condition and 13 rated scour-critical. Poor-condition bridges carry about 20,643 daily vehicle crossings. Poor condition does not mean unsafe; bridges judged unsafe are closed or restricted by transportation agencies.

Download all county report-card scores as CSV.

How the Score Breaks Down

Factor	Weight	County Value	Penalty
Poor-condition bridge share	40	1.0%	2.0
Poor-condition traffic exposure	25	0.9% of measured traffic	0.7
Scour-critical bridge share	20	6.5%	13.1
Average age vs national baseline	10	47 years vs 48 nationally	0.0
Traffic-data completeness	5	2,211,423 measured daily crossings	0.0

Score = 100 minus weighted penalties. The score is a comparative research signal, not an official safety rating. Read the full methodology.

County Comparisons

County Poor-Condition Share	1.0%
State Poor-Condition Share	5.6%
National Poor-Condition Share	6.7%
County Scour-Critical Share	6.5%
Average Bridge Age	47 years
Poor-Condition Traffic Exposure	20,643 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeCapitol BLVD over I-5 Ramp — 13,767 vehicles/day Oldest Listed BridgeBoston Street over Deschutes River — built in 1915 All County BridgesBrowse every bridge record in Thurston County.

Top Bridges to Watch in Thurston County

Bridge	Reason	Condition	Daily Traffic	Year Built
Capitol BLVD over I-5 Ramp	Poor condition + traffic exposure	Poor	13,767	1956
Plum-n Ramp over Eastside ST SE	Poor condition + traffic exposure	Poor	6,876	1957
US 12 over Scatter Creek	Scour-critical foundation rating	Fair	13,337	1926
SR 507 over Deschutes River	Scour-critical foundation rating	Fair	5,190	1943
Old HWY No. 9 over Prairie Creek	Scour-critical foundation rating	Fair	3,433	1936
Case Road over Beaver Creek	Scour-critical foundation rating	Fair	3,040	1970
Case Road SW over Scatter Creek	Scour-critical foundation rating	Fair	2,751	1965
Independence Road over Chehalis River	Scour-critical foundation rating	Fair	1,409	1976
Waddell Creek Road over Waddell Creek	Scour-critical foundation rating	Good	1,164	1969
Vail Cutoff RD over Deschutes River	Scour-critical foundation rating	Fair	1,079	1956

Important safety note

Poor condition does not mean a bridge is unsafe. It means at least one major component has significant deterioration and the bridge is a priority for maintenance, repair, or replacement. Bridges judged unsafe are closed or restricted by transportation agencies.