Bannock County Bridge Report Card

Bannock County scores 80 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

B80 / 100

Local infrastructure snapshot

Bannock County, Idaho

Bannock County has 128 bridges in the National Bridge Inventory, with 6 rated poor and 5 rated scour-critical. Its poor-condition share of 4.7% is at or below the 5.4% statewide average. Poor-condition bridges carry about 27,300 daily vehicle crossings.

128Total Bridges

6Poor (4.7%)

74Fair (57.8%)

5Scour-Critical

Quote-Ready Local Facts

4.7%of county bridges are in poor condition, compared with 5.4% statewide and 6.7% nationally.

27,300daily vehicle crossings are on poor-condition bridges in the county.

5bridges are rated scour-critical, or 3.9% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Bannock County a Bridge Condition Exposure Score of 80/100 (B). The county has 128 bridges in the National Bridge Inventory, including 6 in poor condition and 5 rated scour-critical. Poor-condition bridges carry about 27,300 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	4.7%	9.4
Poor-condition traffic exposure	25	3.2% of measured traffic	2.4
Scour-critical bridge share	20	3.9%	7.8
Average age vs national baseline	10	42 years vs 48 nationally	0.0
Traffic-data completeness	5	866,133 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	4.7%
State Poor-Condition Share	5.4%
National Poor-Condition Share	6.7%
County Scour-Critical Share	3.9%
Average Bridge Age	42 years
Poor-Condition Traffic Exposure	27,300 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeI 15 Nbl over Main Street Gs — 7,750 vehicles/day Oldest Listed BridgeUS 91 over Tyhee Wasteway Canal — built in 1925 All County BridgesBrowse every bridge record in Bannock County.

Top Bridges to Watch in Bannock County

Bridge	Reason	Condition	Daily Traffic	Year Built
Stc 1757;main ST over Portneuf River	Poor condition + traffic exposure	Poor	1,200	1962
I 15 Nbl over Main Street Gs	Poor condition + traffic exposure	Poor	7,750	1962
I 15 Sbl over Main Street Gs	Poor condition + traffic exposure	Poor	7,750	1962
I 15 Nbl over I 15b;w.inkom Ic	Poor condition + traffic exposure	Poor	7,750	1962
Stc7151;benton ST over Portneuf River	Poor condition + traffic exposure	Poor	2,800	1969
E. Sublette Road over Portneuf Marsh Val.cnl	Poor condition + traffic exposure	Poor	50	1968
I 15 Nbl over Portneuf River	Scour-critical foundation rating	Fair	8,000	1963
I 15 Sbl over Portneuf River	Scour-critical foundation rating	Fair	8,000	1963
US 30 over Portneuf River;mccammon	Scour-critical foundation rating	Fair	4,700	1963
N Kraft Road over Portneuf River	Scour-critical foundation rating	Fair	100	1945

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.