US Bridges

US Highway 101 NB over S101-MISSION ST Off-Ramp

Good

San Luis Obispo County, California · 05-SLO-101-67.23 · Structure no. 49 0164R

Built
1957
68 years old, rebuilt 2020
Condition
Good
inspected November 2023
Type
Tee Beam
Concrete Continuous
Length
150 ft
3 main spans
Daily traffic
8,750
2009 count
Owner
State
State Highway Agency

About this bridge

US Highway 101 NB over S101-MISSION ST Off-Ramp is a concrete continuous tee beam carrying US Highway 101 NB over S101-MISSION ST Off-Ramp in San Luis Obispo County, California. It was built in 1957 and reconstructed in 2020, so it is 68 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 8,750 vehicles a day, roughly 17% of them trucks, projected to reach 17,084 by 2045. The structure is 150 ft (45.7 m) long and 42 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

CarriesUS Highway 101 NB
CrossesS101-MISSION ST Off-Ramp
Location05-SLO-101-67.23
RouteU.S. Route 101
Coordinates35.77043, -120.70511
Functional classRural Principal Arterial - Other

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 inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating42.9 US tons
Inventory rating32.8 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length150 ft (45.7 m)
Longest span60 ft (18.3 m)
Deck width42 ft (12.7 m)
Roadway width39 ft (11.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,750 (2009)
Projected traffic17,084 by 2045
Trucks17%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed0.6 mi (1 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkNon-Interstate STRAHNET route

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 US Highway 101 NB over S101-MISSION ST Off-Ramp built?

It was built in 1957, making it 68 years old in 2025. It was reconstructed in 2020.

What condition is US Highway 101 NB over S101-MISSION ST Off-Ramp 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 November 2023.

How much traffic does US Highway 101 NB over S101-MISSION ST Off-Ramp carry?

About 8,750 vehicles per day (2009 count), of which roughly 17% are trucks.

How long is US Highway 101 NB over S101-MISSION ST Off-Ramp?

The structure is 150 ft (45.7 m) long with a longest span of 60 ft (18.3 m) and a deck 42 ft wide.

Who owns US Highway 101 NB over S101-MISSION ST Off-Ramp?

It is owned by the State Highway Agency.