US Bridges

NM-1 over I-25 Nbl and Sbl

Good

Socorro County, New Mexico · 5.1 MI N of I-25/US-380 · Structure no. 000000000006485

Built
1965
60 years old
Condition
Good
inspected February 2025
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
233 ft
5 main spans
Daily traffic
1,272
2023 count
Owner
State
State Highway Agency

About this bridge

NM-1 over I-25 Nbl and Sbl is a prestressed concrete stringer/multi-beam or girder carrying NM-1 over I-25 Nbl and Sbl in Socorro County, New Mexico. It was built in 1965, so it is 60 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 1,272 vehicles a day, roughly 11% of them trucks, projected to reach 1,729 by 2043. The structure is 233 ft (71 m) long and 32 ft wide. If it were closed, the detour would be 5 mi (8 km).

CarriesNM-1
CrossesI-25 Nbl and Sbl
Location5.1 MI N of I-25/US-380
RouteState Highway 1
Coordinates33.99117, -106.89321
Functional classRural Minor Collector

Condition and inspection

Good

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating63.9 US tons
Inventory rating35.1 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length233 ft (71 m)
Longest span52 ft (15.8 m)
Deck width32 ft (9.8 m)
Roadway width28 ft (8.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,272 (2023)
Projected traffic1,729 by 2043
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$495,000 (2020 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was NM-1 over I-25 Nbl and Sbl built?

It was built in 1965, making it 60 years old in 2025.

What condition is NM-1 over I-25 Nbl and Sbl 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 February 2025.

How much traffic does NM-1 over I-25 Nbl and Sbl carry?

About 1,272 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is NM-1 over I-25 Nbl and Sbl?

The structure is 233 ft (71 m) long with a longest span of 52 ft (15.8 m) and a deck 32 ft wide.

Who owns NM-1 over I-25 Nbl and Sbl?

It is owned by the State Highway Agency.