US Bridges

CR 4320 over Chiamon Bayou

Good

San Augustine County, Texas · 1.35 MI SE of FM 1751 · Structure no. 112030AA0172001

Built
2015
10 years old
Condition
Good
inspected May 2023
Type
Slab
Prestressed Concrete
Length
40 ft
1 main span
Daily traffic
55
2015 count
Owner
County
County Highway Agency

About this bridge

CR 4320 over Chiamon Bayou is a prestressed concrete slab carrying CR 4320 over Chiamon Bayou in San Augustine County, Texas. It was built in 2015, so it is 10 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 55 vehicles a day, projected to reach 60 by 2035. The structure is 40 ft (12.2 m) long and 27 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesCR 4320
CrossesChiamon Bayou
Location1.35 MI SE of FM 1751
RouteCounty Highway 4320
CountySan Augustine County
StateTexas
Coordinates31.35573, -94.07743
Functional classRural Local

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.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment7: Better than present minimum criteria
Operating rating60 US tons
Inventory rating36 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length40 ft (12.2 m)
Longest span40 ft (12.2 m)
Deck width27 ft (8.1 m)
Roadway width25 ft (7.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic55 (2015)
Projected traffic60 by 2035
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 CR 4320 over Chiamon Bayou built?

It was built in 2015, making it 10 years old in 2025.

What condition is CR 4320 over Chiamon Bayou 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 CR 4320 over Chiamon Bayou carry?

About 55 vehicles per day (2015 count).

How long is CR 4320 over Chiamon Bayou?

The structure is 40 ft (12.2 m) long with a longest span of 40 ft (12.2 m) and a deck 27 ft wide.

Who owns CR 4320 over Chiamon Bayou?

It is owned by the County Highway Agency.