US Bridges

State Route 18 over Hillside

Fair

San Bernardino County, California · 08-SBD-018-R12.49 · Structure no. 54 0752

Built
1966
59 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
824 ft
8 main spans
Daily traffic
16,000
2022 count
Owner
State
State Highway Agency

About this bridge

State Route 18 over Hillside is a steel stringer/multi-beam or girder carrying State Route 18 over Hillside in San Bernardino County, California. It was built in 1966, so it is 59 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 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 16,000 vehicles a day, roughly 10% of them trucks, projected to reach 20,000 by 2042. The structure is 824 ft (251.3 m) long and 38 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesState Route 18
CrossesHillside
Location08-SBD-018-R12.49
RouteState Highway 18
CountySan Bernardino County
StateCalifornia
Coordinates34.20889, -117.28525
Functional classRural Minor Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating63.2 US tons
Inventory rating37.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans8
Design loadHS 20
Structure length824 ft (251.3 m)
Longest span111 ft (33.8 m)
Deck width38 ft (11.6 m)
Roadway width55 ft (16.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic16,000 (2022)
Projected traffic20,000 by 2042
Trucks10%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesOther
Detour if closed3.1 mi (5 km)
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—
NavigationNo navigation control on waterway

Frequently asked questions

When was State Route 18 over Hillside built?

It was built in 1966, making it 59 years old in 2025.

What condition is State Route 18 over Hillside 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 October 2024.

How much traffic does State Route 18 over Hillside carry?

About 16,000 vehicles per day (2022 count), of which roughly 10% are trucks.

How long is State Route 18 over Hillside?

The structure is 824 ft (251.3 m) long with a longest span of 111 ft (33.8 m) and a deck 38 ft wide.

Who owns State Route 18 over Hillside?

It is owned by the State Highway Agency.