US Bridges

NM-551 over Unnamed Waterway

Good

Union County, New Mexico · 1.8 MI N of JCT NM-456 · Structure no. 000000000006857

Built
1966
59 years old
Condition
Good
inspected April 2022
Type
Culvert
Concrete
Length
21 ft
2 main spans
Daily traffic
89
2023 count
Owner
State
State Highway Agency

About this bridge

NM-551 over Unnamed Waterway is a concrete culvert carrying NM-551 over Unnamed Waterway in Union County, New Mexico. It was built in 1966, so it is 59 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 good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 89 vehicles a day, roughly 11% of them trucks, projected to reach 121 by 2043. The structure is 21 ft (6.4 m) long. If it were closed, the detour would be 98.8 mi (159 km).

CarriesNM-551
CrossesUnnamed Waterway
Location1.8 MI N of JCT NM-456
RouteState Highway 551
Coordinates36.93218, -103.86813
Functional classRural Major Collector

Condition and inspection

Good

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

ComponentRatingMeaning
Channel and channel protection7 GoodSome minor problems.
Culvert7 GoodSome minor problems.
Last inspectionApril 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating39.2 US tons
Inventory rating35.7 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans2
Design loadHS 20
Structure length21 ft (6.4 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic89 (2023)
Projected traffic121 by 2043
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemNo

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 NM-551 over Unnamed Waterway built?

It was built in 1966, making it 59 years old in 2025.

What condition is NM-551 over Unnamed Waterway 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 April 2022.

How much traffic does NM-551 over Unnamed Waterway carry?

About 89 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is NM-551 over Unnamed Waterway?

The structure is 21 ft (6.4 m) long with a longest span of 10 ft (3 m).

Who owns NM-551 over Unnamed Waterway?

It is owned by the State Highway Agency.