US Bridges

Boston Mill RD over Mill Race

Fair

Linn County, Oregon · 016 MI East Shedd · Structure no. 12289A001300673

Built
1965
60 years old
Condition
Fair
inspected October 2024
Type
Slab
Prestressed Concrete
Length
70 ft
3 main spans
Daily traffic
299
2021 count
Owner
County
County Highway Agency

About this bridge

Boston Mill RD over Mill Race is a prestressed concrete slab carrying Boston Mill RD over Mill Race in Linn County, Oregon. It was built in 1965, so it is 60 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 299 vehicles a day, roughly 15% of them trucks, projected to reach 464 by 2041. The structure is 70 ft (21.3 m) long and 28 ft wide. If it were closed, the detour would be 10.6 mi (17 km).

Location

Open in Google Maps
CarriesBoston Mill RD
CrossesMill Race
Location016 MI East Shedd
RouteCounty Highway A0477
CountyLinn County
StateOregon
Coordinates44.45966, -123.081
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating33.2 US tons
Inventory rating25.7 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckOther
Main spans3
Design loadHS 20
Structure length70 ft (21.3 m)
Longest span30 ft (9.1 m)
Deck width28 ft (8.5 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic299 (2021)
Projected traffic464 by 2041
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed10.6 mi (17 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Boston Mill RD over Mill Race built?

It was built in 1965, making it 60 years old in 2025.

What condition is Boston Mill RD over Mill Race 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 Boston Mill RD over Mill Race carry?

About 299 vehicles per day (2021 count), of which roughly 15% are trucks.

How long is Boston Mill RD over Mill Race?

The structure is 70 ft (21.3 m) long with a longest span of 30 ft (9.1 m) and a deck 28 ft wide.

Who owns Boston Mill RD over Mill Race?

It is owned by the County Highway Agency.