US Bridges

SH 21 WB over Little Brazos River

Good

Brazos County, Texas · 0.7 MI E of FM 50 · Structure no. 170210011604046

Built
1974
51 years old
Condition
Good
inspected February 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
1,120 ft
16 main spans
Daily traffic
8,108
2020 count
Owner
State
State Highway Agency

About this bridge

SH 21 WB over Little Brazos River is a prestressed concrete stringer/multi-beam or girder carrying SH 21 WB over Little Brazos River in Brazos County, Texas. It was built in 1974, so it is 51 years old, older 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 8,108 vehicles a day, projected to reach 9,310 by 2031. The structure is 1,120 ft (341.4 m) long and 50 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesSH 21 WB
CrossesLittle Brazos River
Location0.7 MI E of FM 50
RouteState Highway 21
StateTexas
Coordinates30.6411, -96.52129
Functional classRural Principal Arterial - Other

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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionFebruary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating60 US tons
Inventory rating36 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans16
Design loadHS 20
Structure length1,120 ft (341.4 m)
Longest span70 ft (21.3 m)
Deck width50 ft (15.3 m)
Roadway width47 ft (14.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,108 (2020)
Projected traffic9,310 by 2031
Trucks0%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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—
NavigationNo navigation control on waterway

Frequently asked questions

When was SH 21 WB over Little Brazos River built?

It was built in 1974, making it 51 years old in 2025.

What condition is SH 21 WB over Little Brazos River 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 SH 21 WB over Little Brazos River carry?

About 8,108 vehicles per day (2020 count).

How long is SH 21 WB over Little Brazos River?

The structure is 1,120 ft (341.4 m) long with a longest span of 70 ft (21.3 m) and a deck 50 ft wide.

Who owns SH 21 WB over Little Brazos River?

It is owned by the State Highway Agency.