US Bridges

SR 77;NB over Rillito SPRR

Fair

Pima County, Arizona · 0.11 MI E JCT I 10 · Structure no. 00503

Built
1957
68 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
123 ft
3 main spans
Daily traffic
11,660
2022 count
Owner
State
State Highway Agency

About this bridge

SR 77;NB over Rillito SPRR is a steel continuous stringer/multi-beam or girder carrying SR 77;NB over Rillito SPRR in Pima County, Arizona. It was built in 1957, so it is 68 years old, older than the Arizona average of 47.8 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 11,660 vehicles a day, roughly 6% of them trucks, projected to reach 11,670 by 2042. The structure is 123 ft (37.5 m) long and 41 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesSR 77;NB
CrossesRillito SPRR
Location0.11 MI E JCT I 10
RouteState Highway 77
CountyPima County
StateArizona
Coordinates32.2607, -111.0005
Functional classUrban Other Principal 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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating58 US tons
Inventory rating35.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length123 ft (37.5 m)
Longest span40 ft (12.2 m)
Deck width41 ft (12.5 m)
Roadway width36 ft (11 m)
Vertical clearance over deck20 ft (6.1 m)

Traffic and service

Average daily traffic11,660 (2022)
Projected traffic11,670 by 2042
Trucks6%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesRailroad
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was SR 77;NB over Rillito SPRR built?

It was built in 1957, making it 68 years old in 2025.

What condition is SR 77;NB over Rillito SPRR 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 October 2023.

How much traffic does SR 77;NB over Rillito SPRR carry?

About 11,660 vehicles per day (2022 count), of which roughly 6% are trucks.

How long is SR 77;NB over Rillito SPRR?

The structure is 123 ft (37.5 m) long with a longest span of 40 ft (12.2 m) and a deck 41 ft wide.

Who owns SR 77;NB over Rillito SPRR?

It is owned by the State Highway Agency.