US Bridges

Pa Tpk (I-476) over SR 309

Good

Lehigh County, Pennsylvania · MP 58.88 on I-476 · Structure no. 000000000057204

Built
1955
70 years old, rebuilt 2019
Condition
Good
inspected November 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
95 ft
1 main span
Daily traffic
30,563
2004 count
Owner
Toll Authority
State Toll Authority

About this bridge

Pa Tpk (I-476) over SR 309 is a steel stringer/multi-beam or girder carrying Pa Tpk (I-476) over SR 309 in Lehigh County, Pennsylvania. It was built in 1955 and reconstructed in 2019, so it is 70 years old, older than the Pennsylvania average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 30,563 vehicles a day, roughly 16% of them trucks, projected to reach 41,677 by 2030. The structure is 95 ft (29 m) long and 69 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

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CarriesPa Tpk (I-476)
CrossesSR 309
LocationMP 58.88 on I-476
RouteInterstate 476
CountyLehigh County
StatePennsylvania
Coordinates40.61496, -75.57722
Functional classRural Principal Arterial - Interstate

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation8: Equal to present desirable criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating51.5 US tons
Inventory rating39.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length95 ft (29 m)
Longest span90 ft (27.4 m)
Deck width69 ft (21 m)
Roadway width60 ft (18.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30,563 (2004)
Projected traffic41,677 by 2030
Trucks16%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed9.9 mi (16 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Toll Authority
Maintained byState Toll Authority
Historic statusNot eligible for the National Register of Historic Places
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Pa Tpk (I-476) over SR 309 built?

It was built in 1955, making it 70 years old in 2025. It was reconstructed in 2019.

What condition is Pa Tpk (I-476) over SR 309 in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in November 2023.

How much traffic does Pa Tpk (I-476) over SR 309 carry?

About 30,563 vehicles per day (2004 count), of which roughly 16% are trucks.

How long is Pa Tpk (I-476) over SR 309?

The structure is 95 ft (29 m) long with a longest span of 90 ft (27.4 m) and a deck 69 ft wide.

Who owns Pa Tpk (I-476) over SR 309?

It is owned by the State Toll Authority.