Brown County Bridge Report Card

Brown County scores 52 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

F52 / 100

Local infrastructure snapshot

Brown County, South Dakota

Brown County has 170 bridges in the National Bridge Inventory, with 20 rated poor and 8 rated scour-critical. Its poor-condition share of 11.8% is at or below the 16.1% statewide average. Poor-condition bridges carry about 30,141 daily vehicle crossings.

170Total Bridges

20Poor (11.8%)

95Fair (55.9%)

8Scour-Critical

Quote-Ready Local Facts

11.8%of county bridges are in poor condition, compared with 16.1% statewide and 6.7% nationally.

30,141daily vehicle crossings are on poor-condition bridges in the county.

8bridges are rated scour-critical, or 4.7% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Brown County a Bridge Condition Exposure Score of 52/100 (F). The county has 170 bridges in the National Bridge Inventory, including 20 in poor condition and 8 rated scour-critical. Poor-condition bridges carry about 30,141 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	11.8%	23.5
Poor-condition traffic exposure	25	20.6% of measured traffic	15.4
Scour-critical bridge share	20	4.7%	9.4
Average age vs national baseline	10	42 years vs 48 nationally	0.0
Traffic-data completeness	5	146,600 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	11.8%
State Poor-Condition Share	16.1%
National Poor-Condition Share	6.7%
County Scour-Critical Share	4.7%
Average Bridge Age	42 years
Poor-Condition Traffic Exposure	30,141 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeUs012 over Moccasin Ck — 21,635 vehicles/day Oldest Listed Bridge103rd Street over James River — built in 1900 All County BridgesBrowse every bridge record in Brown County.

Top Bridges to Watch in Brown County

Bridge	Reason	Condition	Daily Traffic	Year Built
Us281 over Elm Rv	Poor condition + traffic exposure	Poor	3,041	1959
Us012 over Moccasin Ck	Poor condition + traffic exposure	Poor	21,635	1954
10th Avenue SE over Moccasin Creek	Poor condition + traffic exposure	Poor	2,069	1974
134th Street over Creek	Poor condition + traffic exposure	Poor	1,400	1930
8th Avenue SE over Moccasin Creek	Poor condition + traffic exposure	Poor	500	1976
396th Avenue over James River	Poor condition + traffic exposure	Poor	252	1957
103rd Street over James River	Poor condition + traffic exposure	Poor	98	1900
398th Avenue over Mud Creek	Poor condition + traffic exposure	Poor	98	1915
125th Street over James River	Poor condition + traffic exposure	Poor	98	1920
373rd Avenue over Snake Creek	Poor condition + traffic exposure	Poor	98	1929

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.