US Bridges

IH 35 Sbml over FM 1581

Fair

Frio County, Texas · IH 35 at FM 1581 · Structure no. 150830001707253

Built
1973
52 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
185 ft
1 main span
Daily traffic
12,750
2019 count
Owner
State
State Highway Agency

About this bridge

IH 35 Sbml over FM 1581 is a prestressed concrete stringer/multi-beam or girder carrying IH 35 Sbml over FM 1581 in Frio County, Texas. It was built in 1973, so it is 52 years old, older than the Texas average of 44.4 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 12,750 vehicles a day, roughly 20% of them trucks, projected to reach 19,130 by 2033. The structure is 185 ft (56.4 m) long and 42 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesIH 35 Sbml
CrossesFM 1581
LocationIH 35 at FM 1581
RouteInterstate 35
CountyFrio County
StateTexas
Coordinates28.88065, -99.11543
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionJuly 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 geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating60 US tons
Inventory rating23 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1 (+2 approach)
Design loadHS 20
Structure length185 ft (56.4 m)
Longest span95 ft (29 m)
Deck width42 ft (12.9 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic12,750 (2019)
Projected traffic19,130 by 2033
Trucks20%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was IH 35 Sbml over FM 1581 built?

It was built in 1973, making it 52 years old in 2025.

What condition is IH 35 Sbml over FM 1581 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 July 2024.

How much traffic does IH 35 Sbml over FM 1581 carry?

About 12,750 vehicles per day (2019 count), of which roughly 20% are trucks.

How long is IH 35 Sbml over FM 1581?

The structure is 185 ft (56.4 m) long with a longest span of 95 ft (29 m) and a deck 42 ft wide.

Who owns IH 35 Sbml over FM 1581?

It is owned by the State Highway Agency.