US Bridges

ST RTE 173 over West Penobscot Bay

Fair

Waldo County, Maine · 0.17 MI Easterly of RTE1 · Structure no. 6342

Built
2009
16 years old
Condition
Fair
inspected June 2024
Type
Movable - Lift
Steel
Length
82 ft
1 main span
Daily traffic
798
2016 count
Owner
State
State Highway Agency

About this bridge

ST RTE 173 over West Penobscot Bay is a steel movable - lift carrying ST RTE 173 over West Penobscot Bay in Waldo County, Maine. It was built in 2009, so it is 16 years old, younger than the Maine average of 53.7 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 798 vehicles a day, roughly 5% of them trucks, projected to reach 1,277 by 2036. The structure is 82 ft (25 m) long and 11 ft wide. If it were closed, the detour would be 100 mi (161 km).

Location

Open in Google Maps
CarriesST RTE 173
CrossesWest Penobscot Bay
Location0.17 MI Easterly of RTE1
RouteState Highway 173
CountyWaldo County
StateMaine
Coordinates44.28044, -69.00586
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating47.2 US tons
Inventory rating36 US tons

Structure

Structure typeMovable - Lift
MaterialSteel
DeckOpen grating
Main spans1
Design loadHS 25 or greater
Structure length82 ft (25 m)
Longest span50 ft (15.2 m)
Deck width11 ft (3.4 m)
Roadway width11 ft (3.4 m)
Vertical clearance over deck15 ft (4.4 m)

Traffic and service

Average daily traffic798 (2016)
Projected traffic1,277 by 2036
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed100 mi (161 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 ST RTE 173 over West Penobscot Bay built?

It was built in 2009, making it 16 years old in 2025.

What condition is ST RTE 173 over West Penobscot Bay 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 June 2024.

How much traffic does ST RTE 173 over West Penobscot Bay carry?

About 798 vehicles per day (2016 count), of which roughly 5% are trucks.

How long is ST RTE 173 over West Penobscot Bay?

The structure is 82 ft (25 m) long with a longest span of 50 ft (15.2 m) and a deck 11 ft wide.

Who owns ST RTE 173 over West Penobscot Bay?

It is owned by the State Highway Agency.