US Bridges

NM-578 over Roadway Slide Area

Fair

Taos County, New Mexico · 1.40 MI S of JCT NM-38 · Structure no. 000000000007525

Built
1975
50 years old
Condition
Fair
inspected June 2024
Type
Slab
Concrete Continuous
Length
142 ft
6 main spans
Daily traffic
838
2023 count
Owner
State
State Highway Agency

About this bridge

NM-578 over Roadway Slide Area is a concrete continuous slab carrying NM-578 over Roadway Slide Area in Taos County, New Mexico. It was built in 1975, so it is 50 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 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.

It carries about 838 vehicles a day, roughly 11% of them trucks, projected to reach 1,139 by 2043. The structure is 142 ft (43.3 m) long and 35 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesNM-578
CrossesRoadway Slide Area
Location1.40 MI S of JCT NM-38
RouteState Highway 578
CountyTaos County
StateNew Mexico
Coordinates36.68799, -105.38579
Functional classRural Major 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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment7: Better than present minimum criteria
Operating rating67.1 US tons
Inventory rating40.1 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length142 ft (43.3 m)
Longest span25 ft (7.6 m)
Deck width35 ft (10.7 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic838 (2023)
Projected traffic1,139 by 2043
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesOther
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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$4 million
NavigationNo navigation control on waterway

Frequently asked questions

When was NM-578 over Roadway Slide Area built?

It was built in 1975, making it 50 years old in 2025.

What condition is NM-578 over Roadway Slide Area 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 June 2024.

How much traffic does NM-578 over Roadway Slide Area carry?

About 838 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is NM-578 over Roadway Slide Area?

The structure is 142 ft (43.3 m) long with a longest span of 25 ft (7.6 m) and a deck 35 ft wide.

Who owns NM-578 over Roadway Slide Area?

It is owned by the State Highway Agency.