US Bridges

US 77 SB over M ST

Good

Cameron County, Texas · 0.70 MI NW of FM 1479 · Structure no. 210310003907303

Built
2004
21 years old
Condition
Good
inspected February 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
227 ft
1 main span
Daily traffic
34,270
2011 count
Owner
State
State Highway Agency

About this bridge

US 77 SB over M ST is a steel continuous stringer/multi-beam or girder carrying US 77 SB over M ST in Cameron County, Texas. It was built in 2004, so it is 21 years old, younger than the Texas average of 44.4 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 34,270 vehicles a day, roughly 8% of them trucks, projected to reach 47,980 by 2031. The structure is 227 ft (69.2 m) long and 83 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesUS 77 SB
CrossesM ST
Location0.70 MI NW of FM 1479
RouteU.S. Route 77
StateTexas
Coordinates26.17933, -97.71034
Functional classUrban Principal Arterial - Other Freeway or Expressway

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 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating75 US tons
Inventory rating45 US tons

Structure

MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans1 (+2 approach)
Design loadHS 25 or greater
Structure length227 ft (69.2 m)
Longest span102 ft (31.1 m)
Deck width83 ft (25.3 m)
Roadway width81 ft (24.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic34,270 (2011)
Projected traffic47,980 by 2031
Trucks8%
Lanes on structure5
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkNon-Interstate STRAHNET route

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 US 77 SB over M ST built?

It was built in 2004, making it 21 years old in 2025.

What condition is US 77 SB over M ST 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 2023.

How much traffic does US 77 SB over M ST carry?

About 34,270 vehicles per day (2011 count), of which roughly 8% are trucks.

How long is US 77 SB over M ST?

The structure is 227 ft (69.2 m) long with a longest span of 102 ft (31.1 m) and a deck 83 ft wide.

Who owns US 77 SB over M ST?

It is owned by the State Highway Agency.