US Bridges

FM 491 over Mercedes Canal

Good

Hidalgo County, Texas · 2.7 MI N of US 83 · Structure no. 211090086101017

Built
2007
18 years old
Condition
Good
inspected May 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
75 ft
1 main span
Daily traffic
2,704
2020 count
Owner
State
State Highway Agency

About this bridge

FM 491 over Mercedes Canal is a prestressed concrete box beam or girders - multiple carrying FM 491 over Mercedes Canal in Hidalgo County, Texas. It was built in 2007, so it is 18 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 2,704 vehicles a day, roughly 35% of them trucks, projected to reach 3,300 by 2033. The structure is 75 ft (22.9 m) long and 46 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesFM 491
CrossesMercedes Canal
Location2.7 MI N of US 83
RouteState Highway 491
CountyHidalgo County
StateTexas
Coordinates26.19459, -97.9108
Functional classUrban 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.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour evaluation has not been made
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating60 US tons
Inventory rating36 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length75 ft (22.9 m)
Longest span75 ft (22.9 m)
Deck width46 ft (14 m)
Roadway width44 ft (13.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,704 (2020)
Projected traffic3,300 by 2033
Trucks35%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM 491 over Mercedes Canal built?

It was built in 2007, making it 18 years old in 2025.

What condition is FM 491 over Mercedes Canal 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 May 2023.

How much traffic does FM 491 over Mercedes Canal carry?

About 2,704 vehicles per day (2020 count), of which roughly 35% are trucks.

How long is FM 491 over Mercedes Canal?

The structure is 75 ft (22.9 m) long with a longest span of 75 ft (22.9 m) and a deck 46 ft wide.

Who owns FM 491 over Mercedes Canal?

It is owned by the State Highway Agency.