US Bridges

SH 21 WB over Thompson Creek Relief

Good

Brazos County, Texas · 2.7 MI SW of FM 2818 · Structure no. 170210011604041

Built
1970
55 years old
Condition
Good
inspected February 2023
Type
Stringer/Multi-beam or Girder
Concrete
Length
152 ft
5 main spans
Daily traffic
4,875
2020 count
Owner
State
State Highway Agency

About this bridge

SH 21 WB over Thompson Creek Relief is a concrete stringer/multi-beam or girder carrying SH 21 WB over Thompson Creek Relief in Brazos 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 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 4,875 vehicles a day, roughly 12% of them trucks, projected to reach 6,680 by 2033. The structure is 152 ft (46.3 m) long and 44 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSH 21 WB
CrossesThompson Creek Relief
Location2.7 MI SW of FM 2818
RouteState Highway 21
CountyBrazos County
StateTexas
Coordinates30.65355, -96.44675
Functional classUrban Other Principal Arterial

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 inspectionFebruary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating75 US tons
Inventory rating45 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length152 ft (46.3 m)
Longest span30 ft (9.1 m)
Deck width44 ft (13.5 m)
Roadway width41 ft (12.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,875 (2020)
Projected traffic6,680 by 2033
Trucks12%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesRelief for waterway
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 Thompson Creek Relief built?

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

What condition is SH 21 WB over Thompson Creek Relief 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 Thompson Creek Relief carry?

About 4,875 vehicles per day (2020 count), of which roughly 12% are trucks.

How long is SH 21 WB over Thompson Creek Relief?

The structure is 152 ft (46.3 m) long with a longest span of 30 ft (9.1 m) and a deck 44 ft wide.

Who owns SH 21 WB over Thompson Creek Relief?

It is owned by the State Highway Agency.