Mason County Bridge Report Card

Mason County scores 72 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

C72 / 100

Local infrastructure snapshot

Mason County, Washington

Mason County has 136 bridges in the National Bridge Inventory, with 4 rated poor and 12 rated scour-critical. Its poor-condition share of 2.9% is at or below the 5.6% statewide average. Poor-condition bridges carry about 18,526 daily vehicle crossings.

136Total Bridges

4Poor (2.9%)

55Fair (40.4%)

12Scour-Critical

Quote-Ready Local Facts

2.9%of county bridges are in poor condition, compared with 5.6% statewide and 6.7% nationally.

18,526daily vehicle crossings are on poor-condition bridges in the county.

12bridges are rated scour-critical, or 8.8% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Mason County a Bridge Condition Exposure Score of 72/100 (C). The county has 136 bridges in the National Bridge Inventory, including 4 in poor condition and 12 rated scour-critical. Poor-condition bridges carry about 18,526 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	2.9%	5.9
Poor-condition traffic exposure	25	4.5% of measured traffic	3.3
Scour-critical bridge share	20	8.8%	17.6
Average age vs national baseline	10	49 years vs 48 nationally	0.6
Traffic-data completeness	5	415,020 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	2.9%
State Poor-Condition Share	5.6%
National Poor-Condition Share	6.7%
County Scour-Critical Share	8.8%
Average Bridge Age	49 years
Poor-Condition Traffic Exposure	18,526 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeUS 101 over Matlock RD — 18,182 vehicles/day Oldest Listed BridgeOld Olympic Highwa over Kennedy Creek — built in 1917 All County BridgesBrowse every bridge record in Mason County.

Top Bridges to Watch in Mason County

Bridge	Reason	Condition	Daily Traffic	Year Built
US 101 over Matlock RD	Poor condition + traffic exposure	Poor	18,182	1973
Agate Loop RD over Campbell Creek	Poor condition + traffic exposure	Poor	257	1950
W. Bulb Farm Rd. over Cloquallum Creek	Poor condition + traffic exposure	Poor	62	1961
No Data Entered over Lena Creek	Poor condition + traffic exposure	Poor	25	1964
SR 3 over Johns Creek	Scour-critical foundation rating	Fair	15,751	1948
US 101 over Kennedy Creek	Scour-critical foundation rating	Fair	13,297	1960
US 101 over Kennedy Creek	Scour-critical foundation rating	Fair	13,297	1960
SR 3 over Sherwood Creek	Scour-critical foundation rating	Fair	10,739	1952
SR 300 over Mission Creek	Scour-critical foundation rating	Fair	7,374	1963
Shelton Matlock RD over Goldsborough Creek	Scour-critical foundation rating	Good	2,079	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.