PA TPK (I-476)

over US6&11 SR0407 CP RR

CLARKS SUMMIT BOROUGH, Lackawanna County, Pennsylvania

Condition

Fair

Year Built

1955

Daily Traffic

6,895

Length

163 ft

About This Bridge

PA TPK (I-476) carries traffic over US6&11 SR0407 CP RR in Lackawanna County, Pennsylvania. Built in 1955, this structure is 71 years old, placing it among the older bridges still in active service. The bridge features steel continuous construction with a girder and floorbeam design, a combination chosen by engineers to meet the specific requirements of this crossing.

Approximately 6,895 vehicles cross this bridge daily, indicating lower traffic volumes common for local roads and rural routes. While traffic is lighter, these bridges still serve essential community transportation needs. Commercial trucks account for 19% of all crossings. This heavy commercial usage significantly impacts structural wear, as a single fully-loaded truck can cause as much deck wear as thousands of passenger vehicles. Transportation planners factor this into maintenance scheduling and budget allocation.

The bridge is currently rated in fair condition based on federal inspection criteria established by the Federal Highway Administration. The structure meets current safety standards for its designated use and load capacity. With a total length of 163 feet, this structure falls within the typical range requiring standard inspection procedures conducted by certified bridge inspectors.

The construction materials used in this bridge were selected based on engineering requirements, cost considerations, and local conditions at the time of construction.

Federal law requires that all highway bridges be inspected at least every 24 months by qualified inspectors following the National Bridge Inspection Standards (NBIS). Some bridges with known issues or unusual characteristics may be inspected more frequently. Inspection data is reported to the National Bridge Inventory, a database maintained by the Federal Highway Administration that tracks the condition of all public highway bridges in the United States. This bridge data is sourced from that federal database and reflects the most recent available inspection results.

Condition Ratings

7

Deck Condition

Good

5

Superstructure

Fair

6

Substructure

Satisfactory

8

Channel & Protection

Very Good

5

Lowest Rating

Determines condition category

NBI condition ratings range from 0 (failed) to 9 (excellent). Ratings of 4 or below are considered poor. The overall condition category is determined by the lowest individual component rating.

The fair condition rating of 5 indicates some deterioration that warrants monitoring but doesn't affect structural integrity.

For a structure built in 1955, this condition level is expected given the bridge's age and usage patterns.

Bridge Details

Steel Continuous is the primary structural material, which influences maintenance requirements and expected lifespan. The girder and floorbeam design was selected based on span requirements, load capacity needs, and site conditions at the time of construction. Maintenance responsibility falls to State Toll Authority.

Construction

Year Built1955
Year Reconstructed2015
MaterialSteel Continuous
Design TypeGirder and Floorbeam
OwnerState Toll Authority

Dimensions

Total Length163 ft (49.6 m)
Max Span17 ft (5.2 m)
Deck Width6 ft
Deck Area9,224 sq ft

Span dimensions affect structural design choices and load distribution. The deck area of 9,224 sq ft determines surface maintenance scope.

Classification

Route TypeInterstate
Route Number476
Lanes On Bridge4
Lanes Under Bridge7

Status

Toll BridgeYes
Historical SignificanceNot determined
Scour Critical8
Detour Length

Traffic Data

Traffic volume data helps engineers assess bridge wear patterns and plan maintenance schedules. Average Daily Traffic (ADT) counts are updated periodically and represent typical weekday usage.

6,895

Avg Daily Traffic (2001)

Vehicles per day crossing this bridge

19%

Truck Traffic

Commercial vehicle percentage

10,187

Projected Future ADT

Estimated future demand

This bridge carries approximately 6,895 vehicles per day, translating to roughly 2,516,675 crossings annually. Lower traffic volumes generally result in less structural wear over time.

Commercial trucks comprise 19% of traffic. Heavy vehicles cause disproportionate wear—a single fully loaded truck can have the impact of thousands of passenger cars on bridge deck surfaces. This high percentage of truck traffic may accelerate deterioration of deck surfaces and structural components.

Traffic projections estimate future volumes of 10,187 vehicles daily, a 48% increase from current levels. These projections inform capacity planning and potential upgrade requirements.

Load Ratings

Load ratings determine what weight this bridge can safely support. These values are critical for routing heavy vehicles and issuing overweight permits.

Operating Rating

5.8 tons

Maximum allowable load for special permits

Inventory Rating

3.5 tons

Load level for normal traffic

The operating rating of 5.8 tons represents the absolute maximum load this bridge can carry under controlled conditions with special permits. The inventory rating of 3.5 tons is the safe load limit for everyday traffic without restrictions. These relatively low ratings may result in posted weight limits or route restrictions for heavy vehicles.

5-Year Condition Trend

Stable

Condition has remained relatively stable since 2020

Data: 2020-2024 FHWA National Bridge Inventory

Location

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41.483333, -76.516667

Identification

Structure Number000000000020957
NBI IDPA-000000000020957
State FIPS42
County FIPS069

Explore More

Data Source: Federal Highway Administration (FHWA) National Bridge Inventory 2024

Bridge inspection data is typically updated every 24 months. Conditions may have changed since the last inspection.

“Structurally deficient” does not mean a bridge is unsafe or likely to collapse. It indicates that one or more key structural elements are in poor or worse condition. Bridges are inspected regularly and may have load restrictions in place.

This data is for informational purposes only and should not be used for route clearance or vehicle weight decisions.

PA TPK (I-476) over US6&11 SR0407 CP RR | Pennsylvania