US Bridges

RD 4280 over Unnamed Wash

Good

San Juan County, New Mexico · 3.9 MI E-Ne Navajo Dam · Structure no. 0405-712

Built
2023
2 years old
Condition
Good
inspected November 2023
Type
Stringer/Multi-beam or Girder
Concrete
Length
87 ft
1 main span
Daily traffic
100
2023 count
Owner
Federal
Bureau of Reclamation

About this bridge

RD 4280 over Unnamed Wash is a concrete stringer/multi-beam or girder carrying RD 4280 over Unnamed Wash in San Juan County, New Mexico. It was built in 2023, so it is 2 years old, younger than the New Mexico average of 51.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 100 vehicles a day, roughly 10% of them trucks, projected to reach 150 by 2043. The structure is 87 ft (26.6 m) long and 35 ft wide. If it were closed, the detour would be 198.8 mi (320 km).

Location

Open in Google Maps
CarriesRD 4280
CrossesUnnamed Wash
Location3.9 MI E-Ne Navajo Dam
RouteFederal Lands Road 4280
CountySan Juan County
StateNew Mexico
Coordinates36.81036, -107.67939
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating55.7 US tons
Inventory rating43.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length87 ft (26.6 m)
Longest span85 ft (25.9 m)
Deck width35 ft (10.7 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2023)
Projected traffic150 by 2043
Trucks10%
Lanes on structure2
Traffic directionHighway traffic not carried
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed198.8 mi (320 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerBureau of Reclamation
Maintained byState Park, Forest, or Reservation Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was RD 4280 over Unnamed Wash built?

It was built in 2023, making it 2 years old in 2025.

What condition is RD 4280 over Unnamed Wash in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in November 2023.

How much traffic does RD 4280 over Unnamed Wash carry?

About 100 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is RD 4280 over Unnamed Wash?

The structure is 87 ft (26.6 m) long with a longest span of 85 ft (25.9 m) and a deck 35 ft wide.

Who owns RD 4280 over Unnamed Wash?

It is owned by the Bureau of Reclamation and maintained by the State Park, Forest, or Reservation Agency.