US Bridges

Conshohocken Road over Upper Merion & Plymouth

Fair

Montgomery County, Pennsylvania · Plymouth TWP.35D01/3367K8 · Structure no. 000000000027706

Built
1964
61 years old
Condition
Fair
inspected October 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
60 ft
1 main span
Daily traffic
8,361
2024 count
Owner
Railroad
Railroad

About this bridge

Conshohocken Road over Upper Merion & Plymouth is a prestressed concrete box beam or girders - multiple carrying Conshohocken Road over Upper Merion & Plymouth in Montgomery County, Pennsylvania. It was built in 1964, so it is 61 years old, older than the Pennsylvania average of 54.8 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 8,361 vehicles a day, roughly 22% of them trucks, projected to reach 9,664 by 2032. The structure is 60 ft (18.3 m) long and 70 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

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CarriesConshohocken Road
CrossesUpper Merion & Plymouth
LocationPlymouth TWP.35D01/3367K8
RouteState Highway 0
CountyMontgomery County
StatePennsylvania
Coordinates40.0823, -75.3158
Functional classUrban Minor Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating89 US tons
Inventory rating47 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length60 ft (18.3 m)
Longest span59 ft (18 m)
Deck width70 ft (21.4 m)
Roadway width69 ft (21.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,361 (2024)
Projected traffic9,664 by 2032
Trucks22%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway and railroad
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerRailroad
Maintained byRailroad
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$550,000
NavigationNot applicable (no waterway)

Frequently asked questions

When was Conshohocken Road over Upper Merion & Plymouth built?

It was built in 1964, making it 61 years old in 2025.

What condition is Conshohocken Road over Upper Merion & Plymouth 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 2023.

How much traffic does Conshohocken Road over Upper Merion & Plymouth carry?

About 8,361 vehicles per day (2024 count), of which roughly 22% are trucks.

How long is Conshohocken Road over Upper Merion & Plymouth?

The structure is 60 ft (18.3 m) long with a longest span of 59 ft (18 m) and a deck 70 ft wide.

Who owns Conshohocken Road over Upper Merion & Plymouth?

It is owned by the Railroad.