Sioux County Bridge Report Card

Sioux County scores 85 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

B85 / 100

Local infrastructure snapshot

Sioux County, North Dakota

Sioux County has 22 bridges in the National Bridge Inventory, with 1 rated poor and 0 rated scour-critical. Its poor-condition share of 4.5% is at or below the 11.1% statewide average. Poor-condition bridges carry about 401 daily vehicle crossings.

22Total Bridges

1Poor (4.5%)

9Fair (40.9%)

0Scour-Critical

Quote-Ready Local Facts

4.5%of county bridges are in poor condition, compared with 11.1% statewide and 6.7% nationally.

401daily vehicle crossings are on poor-condition bridges in the county.

0bridges are rated scour-critical, or 0.0% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Sioux County a Bridge Condition Exposure Score of 85/100 (B). The county has 22 bridges in the National Bridge Inventory, including 1 in poor condition and 0 rated scour-critical. Poor-condition bridges carry about 401 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	4.5%	9.1
Poor-condition traffic exposure	25	4.2% of measured traffic	3.1
Scour-critical bridge share	20	0.0%	0.0
Average age vs national baseline	10	56 years vs 48 nationally	3.2
Traffic-data completeness	5	9,591 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	4.5%
State Poor-Condition Share	11.1%
National Poor-Condition Share	6.7%
County Scour-Critical Share	0.0%
Average Bridge Age	56 years
Poor-Condition Traffic Exposure	401 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeIRR BIA RTE 29 over One Mile Creek — 401 vehicles/day Oldest Listed BridgeIrrsr Nd Hiway 24 over Four Mile Creek — built in 1930 All County BridgesBrowse every bridge record in Sioux County.

Top Bridges to Watch in Sioux County

Bridge	Reason	Condition	Daily Traffic	Year Built
IRR BIA RTE 29 over One Mile Creek	Poor condition + traffic exposure	Poor	401	1950
Irrsr Nd Hiway 24 over Beaver Holes Creek	High traffic	Fair	1,830	1965
Irrsr Nd Hiway 24 over Porcupine Creek	High traffic	Fair	1,740	1963
Irrsr Nd Hiway 24 over Battle Creek	High traffic	Fair	1,700	1965
IRR BIA RTE 3 over Four Mile Creek Bridge	High traffic	Good	1,000	2010
Irrsr Nd Hiway 24 over Four Mile Creek	High traffic	Fair	750	1930
Irrsr Nd Highway 6 over Porcupine Creek	High traffic	Fair	270	1987
Irrsr Nd Highway 6 over Creek	High traffic	Good	250	1948
Irrsr Nd Highway 6 over Creek	High traffic	Good	250	1949
Irrsr Nd Highway 6 over Creek	High traffic	Good	250	1987

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.