US Bridges

IH 35 over Onion Branch

Fair

Williamson County, Texas · 0.86 MI S of FM 3406 · Structure no. 142460001509176

Built
1960
65 years old, rebuilt 2006
Condition
Fair
inspected January 2023
Type
Culvert
Concrete
Length
107 ft
7 main spans
Daily traffic
138,115
2019 count
Owner
State
State Highway Agency

About this bridge

IH 35 over Onion Branch is a concrete culvert carrying IH 35 over Onion Branch in Williamson County, Texas. It was built in 1960 and reconstructed in 2006, so it is 65 years old, older than the Texas average of 44.4 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 138,115 vehicles a day, roughly 12% of them trucks, projected to reach 193,361 by 2039. The structure is 107 ft (32.6 m) long.

Location

Open in Google Maps
CarriesIH 35
CrossesOnion Branch
Location0.86 MI S of FM 3406
RouteInterstate 35
CountyWilliamson County
StateTexas
Coordinates30.52353, -97.68952
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44 US tons
Inventory rating26 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans7
Design loadHS 20
Structure length107 ft (32.6 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic138,115 (2019)
Projected traffic193,361 by 2039
Trucks12%
Lanes on structure12
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 IH 35 over Onion Branch built?

It was built in 1960, making it 65 years old in 2025. It was reconstructed in 2006.

What condition is IH 35 over Onion Branch in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in January 2023.

How much traffic does IH 35 over Onion Branch carry?

About 138,115 vehicles per day (2019 count), of which roughly 12% are trucks.

How long is IH 35 over Onion Branch?

The structure is 107 ft (32.6 m) long with a longest span of 10 ft (3 m).

Who owns IH 35 over Onion Branch?

It is owned by the State Highway Agency.