US Bridges

Silverbell RD over Blanco Wash

PoorPosted for load

Pima County, Arizona · 0.28 MI W of Aguirre R · Structure no. 08259

Built
1935
90 years old, rebuilt 1998
Condition
Poor
inspected July 2023
Type
Truss - Thru
Steel
Length
71 ft
2 main spans
Daily traffic
816
2022 count
Owner
County
County Highway Agency

About this bridge

Silverbell RD over Blanco Wash is a steel truss - thru carrying Silverbell RD over Blanco Wash in Pima County, Arizona. It was built in 1935 and reconstructed in 1998, so it is 90 years old, older than the Arizona average of 47.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 816 vehicles a day, projected to reach 826 by 2042. The structure is 71 ft (21.6 m) long and 12 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesSilverbell RD
CrossesBlanco Wash
Location0.28 MI W of Aguirre R
RouteCounty Highway 0
CountyPima County
StateArizona
Coordinates32.4663, -111.3389
Functional classRural Minor Collector

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating18 US tons
Inventory rating14 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckWood or timber
Main spans2
Design loadUnknown
Structure length71 ft (21.6 m)
Longest span40 ft (12.2 m)
Deck width12 ft (3.7 m)
Roadway width10 ft (3.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic816 (2022)
Projected traffic826 by 2042
Trucks0%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Silverbell RD over Blanco Wash built?

It was built in 1935, making it 90 years old in 2025. It was reconstructed in 1998.

What condition is Silverbell RD over Blanco Wash in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in July 2023.

How much traffic does Silverbell RD over Blanco Wash carry?

About 816 vehicles per day (2022 count).

How long is Silverbell RD over Blanco Wash?

The structure is 71 ft (21.6 m) long with a longest span of 40 ft (12.2 m) and a deck 12 ft wide.

Who owns Silverbell RD over Blanco Wash?

It is owned by the County Highway Agency.