US Bridges

Tower Line Road over SR 58

Fair

Kern County, California · 06-KER-058-R65.68 · Structure no. 50 0365

Built
1970
55 years old
Condition
Fair
inspected September 2023
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
218 ft
2 main spans
Daily traffic
16,500
1998 count
Owner
State
State Highway Agency

About this bridge

Tower Line Road over SR 58 is a concrete continuous box beam or girders - multiple carrying Tower Line Road over SR 58 in Kern County, California. It was built in 1970, so it is 55 years old, older than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 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 16,500 vehicles a day, roughly 15% of them trucks, projected to reach 22,461 by 2041. The structure is 218 ft (66.4 m) long and 34 ft wide.

Location

Open in Google Maps
CarriesTower Line Road
CrossesSR 58
Location06-KER-058-R65.68
RouteCounty Highway 0
CountyKern County
StateCalifornia
Coordinates35.33003, -118.80761
Functional classRural Local

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50.7 US tons
Inventory rating38.9 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20 + Mod
Structure length218 ft (66.4 m)
Longest span108 ft (32.9 m)
Deck width34 ft (10.4 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic16,500 (1998)
Projected traffic22,461 by 2041
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Tower Line Road over SR 58 built?

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

What condition is Tower Line Road over SR 58 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 September 2023.

How much traffic does Tower Line Road over SR 58 carry?

About 16,500 vehicles per day (1998 count), of which roughly 15% are trucks.

How long is Tower Line Road over SR 58?

The structure is 218 ft (66.4 m) long with a longest span of 108 ft (32.9 m) and a deck 34 ft wide.

Who owns Tower Line Road over SR 58?

It is owned by the State Highway Agency.