US Bridges

IRR BIA RTE 50 over Main Drain

FairPosted for load

La Paz County, Arizona · 1.7 KM West of BIA 1 · Structure no. 00000000000H032

Built
1968
57 years old
Condition
Fair
inspected December 2021
Type
Stringer/Multi-beam or Girder
Concrete
Length
75 ft
3 main spans
Daily traffic
110
2021 count
Owner
Federal
Bureau of Indian Affairs

About this bridge

IRR BIA RTE 50 over Main Drain is a concrete stringer/multi-beam or girder carrying IRR BIA RTE 50 over Main Drain in La Paz County, Arizona. It was built in 1968, so it is 57 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 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for load restriction.

It carries about 110 vehicles a day, roughly 15% of them trucks, projected to reach 130 by 2039. The structure is 75 ft (22.9 m) long and 27 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

CarriesIRR BIA RTE 50
CrossesMain Drain
Location1.7 KM West of BIA 1
RouteFederal Lands Road 50
StateArizona
Coordinates33.81048, -114.48531
Functional classRural Minor Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 2021
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating32.6 US tons
Inventory rating23.9 US tons

Structure

MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length75 ft (22.9 m)
Longest span25 ft (7.6 m)
Deck width27 ft (8.3 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic110 (2021)
Projected traffic130 by 2039
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerBureau of Indian Affairs
Maintained byBureau of Indian Affairs
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$52,000 (2021 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was IRR BIA RTE 50 over Main Drain built?

It was built in 1968, making it 57 years old in 2025.

What condition is IRR BIA RTE 50 over Main Drain 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 December 2021.

How much traffic does IRR BIA RTE 50 over Main Drain carry?

About 110 vehicles per day (2021 count), of which roughly 15% are trucks.

How long is IRR BIA RTE 50 over Main Drain?

The structure is 75 ft (22.9 m) long with a longest span of 25 ft (7.6 m) and a deck 27 ft wide.

Who owns IRR BIA RTE 50 over Main Drain?

It is owned by the Bureau of Indian Affairs.