US Bridges

US-550 over Unnamed Waterway

Fair

San Juan County, New Mexico · 7.0 MI N of US 64 · Structure no. 000000000005532

Built
1946
79 years old, rebuilt 1995
Condition
Fair
inspected December 2023
Type
Culvert
Concrete
Length
40 ft
3 main spans
Daily traffic
9,523
2023 count
Owner
State
State Highway Agency

About this bridge

US-550 over Unnamed Waterway is a concrete culvert carrying US-550 over Unnamed Waterway in San Juan County, New Mexico. It was built in 1946 and reconstructed in 1995, so it is 79 years old, older than the New Mexico average of 51.5 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 9,523 vehicles a day, roughly 17% of them trucks, projected to reach 12,951 by 2043. The structure is 40 ft (12.2 m) long.

CarriesUS-550
CrossesUnnamed Waterway
Location7.0 MI N of US 64
RouteU.S. Route 550
Coordinates36.80641, -107.99975
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
Channel and channel protection7 GoodSome minor problems.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionDecember 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating92.8 US tons
Inventory rating35.7 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans3
Design loadHS 20
Structure length40 ft (12.2 m)
Longest span12 ft (3.7 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,523 (2023)
Projected traffic12,951 by 2043
Trucks17%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
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$300,000 (2030 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was US-550 over Unnamed Waterway built?

It was built in 1946, making it 79 years old in 2025. It was reconstructed in 1995.

What condition is US-550 over Unnamed Waterway 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 2023.

How much traffic does US-550 over Unnamed Waterway carry?

About 9,523 vehicles per day (2023 count), of which roughly 17% are trucks.

How long is US-550 over Unnamed Waterway?

The structure is 40 ft (12.2 m) long with a longest span of 12 ft (3.7 m).

Who owns US-550 over Unnamed Waterway?

It is owned by the State Highway Agency.