US Bridges

SH 34 over Bear River;riverdale Br

Fair

Franklin County, Idaho · 5.1 N. Preston · Structure no. 000000000013985

Built
1960
65 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Concrete
Length
216 ft
6 main spans
Daily traffic
2,800
2023 count
Owner
State
State Highway Agency

About this bridge

SH 34 over Bear River;riverdale Br is a concrete stringer/multi-beam or girder carrying SH 34 over Bear River;riverdale Br in Franklin County, Idaho. It was built in 1960, so it is 65 years old, older than the Idaho average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 2,800 vehicles a day, roughly 8% of them trucks, projected to reach 4,200 by 2042. The structure is 216 ft (65.8 m) long and 33 ft wide.

Location

Open in Google Maps
CarriesSH 34
CrossesBear River;riverdale Br
Location5.1 N. Preston
RouteState Highway 34
CountyFranklin County
StateIdaho
Coordinates42.16561, -111.83286
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating57 US tons
Inventory rating34 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length216 ft (65.8 m)
Longest span35 ft (10.7 m)
Deck width33 ft (10 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,800 (2023)
Projected traffic4,200 by 2042
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$2.7 million (2018 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SH 34 over Bear River;riverdale Br built?

It was built in 1960, making it 65 years old in 2025.

What condition is SH 34 over Bear River;riverdale Br in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in July 2024.

How much traffic does SH 34 over Bear River;riverdale Br carry?

About 2,800 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is SH 34 over Bear River;riverdale Br?

The structure is 216 ft (65.8 m) long with a longest span of 35 ft (10.7 m) and a deck 33 ft wide.

Who owns SH 34 over Bear River;riverdale Br?

It is owned by the State Highway Agency.