US Bridges

State Route 18 over Hillside

Good

San Bernardino County, California · 08-SBD-018-R17.54 · Structure no. 54 0684

Built
1965
60 years old
Condition
Good
inspected October 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
949 ft
11 main spans
Daily traffic
16,800
2017 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 1965, so it is 60 years old, older than the California average of 54.8 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 16,800 vehicles a day, roughly 10% of them trucks, projected to reach 20,000 by 2043. The structure is 949 ft (289.4 m) long and 44 ft wide. If it were closed, the detour would be 47.2 mi (76 km).

CarriesState Route 18
CrossesHillside
Location08-SBD-018-R17.54
RouteState Highway 18
Coordinates34.22961, -117.29141
Functional classRural Minor 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.
Last inspectionOctober 2024
Inspection intervalevery 48 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 alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating83.6 US tons
Inventory rating50 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans11
Design loadHS 20
Structure length949 ft (289.4 m)
Longest span90 ft (27.4 m)
Deck width44 ft (13.4 m)
Roadway width55 ft (16.8 m)
Vertical clearance over deck18 ft (5.5 m)

Traffic and service

Average daily traffic16,800 (2017)
Projected traffic20,000 by 2043
Trucks10%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesOther
Detour if closed47.2 mi (76 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 1965, making it 60 years old in 2025.

What condition is State Route 18 over Hillside 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 October 2024.

How much traffic does State Route 18 over Hillside carry?

About 16,800 vehicles per day (2017 count), of which roughly 10% are trucks.

How long is State Route 18 over Hillside?

The structure is 949 ft (289.4 m) long with a longest span of 90 ft (27.4 m) and a deck 44 ft wide.

Who owns State Route 18 over Hillside?

It is owned by the State Highway Agency.