MARINE HWY ROUTE

over COLD BAY DOCK

COLD BAY, Aleutians East Borough, Alaska

Condition

Poor

Year Built

1980

Daily Traffic

10

Length

182 ft

About This Bridge

MARINE HWY ROUTE carries traffic over COLD BAY DOCK in Aleutians East Borough, Alaska. Built in 1980, this structure is 46 years old, built during a period of significant highway expansion. The bridge features prestressed concrete construction with a slab design, a combination chosen by engineers to meet the specific requirements of this crossing.

Approximately 10 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 1% of all crossings. This proportion of commercial traffic is typical for this roadway classification and is factored into the bridge's design load ratings.

The bridge is currently rated in poor condition based on federal inspection criteria established by the Federal Highway Administration. It is classified as structurally deficient, meaning one or more components have received a rating of 4 or below on the 0-9 scale. This designation indicates significant deterioration that warrants attention, though the bridge remains safe for travel within its posted limits. Structurally deficient does not mean unsafe—rather, it signals that repairs or replacement should be prioritized in transportation planning. With a total length of 182 feet, this structure falls within the typical range requiring standard inspection procedures conducted by certified bridge inspectors.

Concrete bridges offer excellent durability and relatively low maintenance requirements. They resist corrosion well but can develop cracking over time, particularly in regions with freeze-thaw cycles or heavy use of deicing chemicals. Regular inspection focuses on detecting cracks, spalling, and reinforcement corrosion.

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

Structurally Deficient

This bridge has one or more component ratings of 4 or below, indicating significant deterioration that requires attention. The bridge remains safe for travel but may have load restrictions.

5

Deck Condition

Fair

4

Superstructure

Poor

4

Substructure

Poor

8

Channel & Protection

Very Good

4

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 superstructure rating of 4 shows advanced deterioration in beams or girders. The substructure rating of 4 reflects significant wear in piers, abutments, or foundations.

For a structure built in 1980, the current condition reflects the cumulative effects of age, traffic, and environmental exposure. If this bridge were closed, traffic would face a detour of approximately 124 miles, underscoring the importance of maintaining this crossing.

Bridge Details

Prestressed Concrete is the primary structural material, which influences maintenance requirements and expected lifespan. The slab design was selected based on span requirements, load capacity needs, and site conditions at the time of construction. Maintenance responsibility falls to County Highway Agency.

Construction

Year Built1980
MaterialPrestressed Concrete
Design TypeSlab
OwnerCounty Highway Agency

Dimensions

Total Length182 ft (55.6 m)
Max Span2 ft (0.7 m)
Deck Width1 ft
Deck Area2,057 sq ft

Span dimensions affect structural design choices and load distribution. The deck area of 2,057 sq ft determines surface maintenance scope.

Classification

Route TypeOther
Route NumberNSP
Lanes On Bridge1
Lanes Under Bridge

Status

Toll BridgeYes
Historical SignificanceNot eligible
Scour CriticalNo
Detour Length124 mi (199 km)

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.

10

Avg Daily Traffic (2018)

Vehicles per day crossing this bridge

1%

Truck Traffic

Commercial vehicle percentage

12

Projected Future ADT

Estimated future demand

This bridge carries approximately 10 vehicles per day, translating to roughly 3,650 crossings annually. Lower traffic volumes generally result in less structural wear over time.

Commercial trucks comprise 1% 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.

Traffic projections estimate future volumes of 12 vehicles daily, a 20% 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

4.1 tons

Maximum allowable load for special permits

Inventory Rating

2.5 tons

Load level for normal traffic

The operating rating of 4.1 tons represents the absolute maximum load this bridge can carry under controlled conditions with special permits. The inventory rating of 2.5 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

Declining

Condition has declined by 1.0 rating points since 2020

Status Changes

  • Entered poor condition in 2021
  • Became structurally deficient in 2021

Data: 2020-2024 FHWA National Bridge Inventory

Location

Loading map...

55.934167, -163.941667

Identification

Structure Number1755
NBI IDAK-1755
State FIPS02
County FIPS013

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.

MARINE HWY ROUTE over COLD BAY DOCK | Alaska