US Bridges

Trinity Lane over Gulph Mills Creek

Fair

Montgomery County, Pennsylvania · Gulph Mills 3367F10 · Structure no. 000000000027402

Built
1789
236 years old, rebuilt 2021
Condition
Fair
inspected January 2024
Type
Arch - Deck
Masonry
Length
22 ft
1 main span
Daily traffic
5,486
2024 count
Owner
State
State Highway Agency

About this bridge

Trinity Lane over Gulph Mills Creek is a masonry arch - deck carrying Trinity Lane over Gulph Mills Creek in Montgomery County, Pennsylvania. It was built in 1789 and reconstructed in 2021, so it is 236 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 5,486 vehicles a day, roughly 10% of them trucks, projected to reach 15,463 by 2032. The structure is 22 ft (6.7 m) long and 34 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesTrinity Lane
CrossesGulph Mills Creek
LocationGulph Mills 3367F10
RouteState Highway 320
CountyMontgomery County
StatePennsylvania
Coordinates40.06892, -75.34058
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
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation6: Equal to present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating91.1 US tons
Inventory rating45 US tons

Structure

Structure typeArch - Deck
MaterialMasonry
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length22 ft (6.7 m)
Longest span20 ft (6.1 m)
Deck width34 ft (10.4 m)
Roadway width31 ft (9.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,486 (2024)
Projected traffic15,463 by 2032
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusListed on the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$486,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Trinity Lane over Gulph Mills Creek built?

It was built in 1789, making it 236 years old in 2025. It was reconstructed in 2021.

What condition is Trinity Lane over Gulph Mills 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 January 2024.

How much traffic does Trinity Lane over Gulph Mills Creek carry?

About 5,486 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is Trinity Lane over Gulph Mills Creek?

The structure is 22 ft (6.7 m) long with a longest span of 20 ft (6.1 m) and a deck 34 ft wide.

Who owns Trinity Lane over Gulph Mills Creek?

It is owned by the State Highway Agency.