US Bridges

Conshohocken ST RD over Mill Creek

Fair

Montgomery County, Pennsylvania · 110 Ft NW SR23 ADC3478-G5 · Structure no. 000000000027985

Built
1932
93 years old
Condition
Fair
inspected May 2024
Type
Arch - Deck
Concrete
Length
70 ft
1 main span
Daily traffic
11,417
2019 count
Owner
County
County Highway Agency

About this bridge

Conshohocken ST RD over Mill Creek is a concrete arch - deck carrying Conshohocken ST RD over Mill Creek in Montgomery County, Pennsylvania. It was built in 1932, so it is 93 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 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 11,417 vehicles a day, roughly 19% of them trucks, projected to reach 10,920 by 2016. The structure is 70 ft (21.3 m) long and 39 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesConshohocken ST RD
CrossesMill Creek
Location110 Ft NW SR23 ADC3478-G5
RouteState Highway 23
CountyMontgomery County
StatePennsylvania
Coordinates40.03149, -75.26957
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
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating68 US tons
Inventory rating41 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans1
Design loadUnknown
Structure length70 ft (21.3 m)
Longest span70 ft (21.3 m)
Deck width39 ft (11.9 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11,417 (2019)
Projected traffic10,920 by 2016
Trucks19%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.7 mi (6 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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$483,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Conshohocken ST RD over Mill Creek built?

It was built in 1932, making it 93 years old in 2025.

What condition is Conshohocken ST RD over Mill 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 May 2024.

How much traffic does Conshohocken ST RD over Mill Creek carry?

About 11,417 vehicles per day (2019 count), of which roughly 19% are trucks.

How long is Conshohocken ST RD over Mill Creek?

The structure is 70 ft (21.3 m) long with a longest span of 70 ft (21.3 m) and a deck 39 ft wide.

Who owns Conshohocken ST RD over Mill Creek?

It is owned by the County Highway Agency.