US Bridges

Thomas Road over Rock Creek

Fair

Clackamas County, Oregon · 30 MI E of HWY 213 · Structure no. 06172 029 00008

Built
1957
68 years old
Condition
Fair
inspected September 2024
Type
Channel Beam
Concrete
Length
23 ft
1 main span
Daily traffic
17,900
2018 count
Owner
County
County Highway Agency

About this bridge

Thomas Road over Rock Creek is a concrete channel beam carrying Thomas Road over Rock Creek in Clackamas County, Oregon. It was built in 1957, so it is 68 years old, older than the Oregon average of 49.9 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 17,900 vehicles a day, roughly 2% of them trucks, projected to reach 19,400 by 2038. The structure is 23 ft (7 m) long and 28 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesThomas Road
CrossesRock Creek
Location30 MI E of HWY 213
RouteCounty Highway 0A606
CountyClackamas County
StateOregon
Coordinates45.11013, -122.59056
Functional classRural Major Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating32.8 US tons
Inventory rating25.4 US tons

Structure

Structure typeChannel Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length23 ft (7 m)
Longest span23 ft (7 m)
Deck width28 ft (8.6 m)
Roadway width25 ft (7.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic17,900 (2018)
Projected traffic19,400 by 2038
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Thomas Road over Rock Creek built?

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

What condition is Thomas Road over Rock Creek 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 2024.

How much traffic does Thomas Road over Rock Creek carry?

About 17,900 vehicles per day (2018 count), of which roughly 2% are trucks.

How long is Thomas Road over Rock Creek?

The structure is 23 ft (7 m) long with a longest span of 23 ft (7 m) and a deck 28 ft wide.

Who owns Thomas Road over Rock Creek?

It is owned by the County Highway Agency.