US Bridges

FM 770 over Mopac Railroad

Fair

Liberty County, Texas · 3.8 MI SW of Hardin C/L · Structure no. 201460109602025

Built
1970
55 years old
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
270 ft
1 main span
Daily traffic
2,761
2022 count
Owner
State
State Highway Agency

About this bridge

FM 770 over Mopac Railroad is a prestressed concrete stringer/multi-beam or girder carrying FM 770 over Mopac Railroad in Liberty County, Texas. It was built in 1970, so it is 55 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 2,761 vehicles a day, roughly 18% of them trucks, projected to reach 4,418 by 2042. The structure is 270 ft (82.3 m) long and 46 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesFM 770
CrossesMopac Railroad
Location3.8 MI SW of Hardin C/L
RouteState Highway 770
CountyLiberty County
StateTexas
Coordinates30.14309, -94.64852
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating62.9 US tons
Inventory rating32 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1 (+4 approach)
Design loadH 20
Structure length270 ft (82.3 m)
Longest span70 ft (21.3 m)
Deck width46 ft (14.1 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,761 (2022)
Projected traffic4,418 by 2042
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad
Detour if closed1.2 mi (2 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 proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was FM 770 over Mopac Railroad built?

It was built in 1970, making it 55 years old in 2025.

What condition is FM 770 over Mopac Railroad 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 May 2024.

How much traffic does FM 770 over Mopac Railroad carry?

About 2,761 vehicles per day (2022 count), of which roughly 18% are trucks.

How long is FM 770 over Mopac Railroad?

The structure is 270 ft (82.3 m) long with a longest span of 70 ft (21.3 m) and a deck 46 ft wide.

Who owns FM 770 over Mopac Railroad?

It is owned by the State Highway Agency.