Ada County Bridge Report Card

Ada County scores 94 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

A94 / 100

Local infrastructure snapshot

Ada County, Idaho

Ada County has 302 bridges in the National Bridge Inventory, with 3 rated poor and 6 rated scour-critical. Its poor-condition share of 1.0% is at or below the 5.4% statewide average. Poor-condition bridges carry about 20,400 daily vehicle crossings.

302Total Bridges

3Poor (1.0%)

165Fair (54.6%)

6Scour-Critical

Quote-Ready Local Facts

1.0%of county bridges are in poor condition, compared with 5.4% statewide and 6.7% nationally.

20,400daily vehicle crossings are on poor-condition bridges in the county.

6bridges are rated scour-critical, or 2.0% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Ada County a Bridge Condition Exposure Score of 94/100 (A). The county has 302 bridges in the National Bridge Inventory, including 3 in poor condition and 6 rated scour-critical. Poor-condition bridges carry about 20,400 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	0.6% of measured traffic	0.4
Scour-critical bridge share	20	2.0%	4.0
Average age vs national baseline	10	36 years vs 48 nationally	0.0
Traffic-data completeness	5	3,648,990 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	5.4%
National Poor-Condition Share	6.7%
County Scour-Critical Share	2.0%
Average Bridge Age	36 years
Poor-Condition Traffic Exposure	20,400 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeSma 7643;healy RD over New York Canal — 7,000 vehicles/day Oldest Listed BridgeSma 8683;black Cat over Five Mile Creek — built in 1930 All County BridgesBrowse every bridge record in Ada County.

Top Bridges to Watch in Ada County

Bridge	Reason	Condition	Daily Traffic	Year Built
Sma 7643;eckert RD over Boise River(barber Br)	Poor condition + traffic exposure	Poor	6,700	1954
Sma 7643;healy RD over New York Canal	Poor condition + traffic exposure	Poor	7,000	1964
Sma 7643;eckert RD over Ridenbaugh Canal	Poor condition + traffic exposure	Poor	6,700	1954
Sma 9773;linder RD over Boise River;n. Channel	Scour-critical foundation rating	Good	22,000	1992
Nhs 7553;capitol over Boise River	Scour-critical foundation rating	Fair	16,500	1931
Stp 7363;americana over Boise River	Scour-critical foundation rating	Fair	12,000	1994
Stp 7343;fairview over Boise River	Scour-critical foundation rating	Fair	5,500	1932
Stp 7343;fairview over Boise River	Scour-critical foundation rating	Fair	5,500	1976
I 84 Ebl & Wbl over Ridenbaugh Canal	High traffic	Fair	144,500	1966
I 84 over Ten Mile Creek	High traffic	Fair	131,000	1965

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.