US Bridges

Islay ST over Mission Creek

Poor

Santa Barbara County, California · At Castillo ST · Structure no. 51C0289

Built
1982
43 years old
Condition
Poor
inspected March 2023
Type
Slab
Concrete Continuous
Length
53 ft
2 main spans
Daily traffic
700
2005 count
Owner
City
City or Municipal Highway Agency

About this bridge

Islay ST over Mission Creek is a concrete continuous slab carrying Islay ST over Mission Creek in Santa Barbara County, California. It was built in 1982, so it is 43 years old, younger than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 700 vehicles a day, roughly 1% of them trucks, projected to reach 657 by 2043. The structure is 53 ft (16.2 m) long and 27 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesIslay ST
CrossesMission Creek
LocationAt Castillo ST
RouteCity Street 0
CountySanta Barbara County
StateCalifornia
Coordinates34.42454, -119.71682
Functional classUrban Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating87.2 US tons
Inventory rating52.5 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20 + Mod
Structure length53 ft (16.2 m)
Longest span31 ft (9.4 m)
Deck width27 ft (8.2 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic700 (2005)
Projected traffic657 by 2043
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$525,000 (2020 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Islay ST over Mission Creek built?

It was built in 1982, making it 43 years old in 2025.

What condition is Islay ST over Mission Creek in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in March 2023.

How much traffic does Islay ST over Mission Creek carry?

About 700 vehicles per day (2005 count), of which roughly 1% are trucks.

How long is Islay ST over Mission Creek?

The structure is 53 ft (16.2 m) long with a longest span of 31 ft (9.4 m) and a deck 27 ft wide.

Who owns Islay ST over Mission Creek?

It is owned by the City or Municipal Highway Agency.