I-75 (SBL)

over ETOWAH RIVER

2.6 MI E OF CARTERSVILLE, Bartow County, Georgia

Condition

Good

Year Built

1977

Daily Traffic

49,000

Length

60 ft

About This Bridge

I-75 (SBL) carries traffic over ETOWAH RIVER in Bartow County, Georgia. Built in 1977, this structure is 49 years old, placing it among the older bridges still in active service. The bridge features prestressed concrete construction with a stringer/multi-beam or girder design, a combination chosen by engineers to meet the specific requirements of this crossing.

Approximately 49,000 vehicles cross this bridge daily, representing moderate traffic volumes typical of important regional connectors. This level of usage requires regular monitoring to ensure continued safe operation. 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 good 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 60 feet, this is a shorter span typical of local road crossings, often carrying traffic over small streams, drainage channels, or other roadways.

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

7

Deck Condition

Good

7

Superstructure

Good

7

Substructure

Good

7

Channel & Protection

Good

7

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.

With a lowest rating of 7, this bridge demonstrates good condition meeting all safety standards.

For a structure built in 1977, maintaining good condition demonstrates effective maintenance practices.

Bridge Details

Prestressed Concrete is the primary structural material, which influences maintenance requirements and expected lifespan. The stringer/multi-beam or girder design was selected based on span requirements, load capacity needs, and site conditions at the time of construction. Maintenance responsibility falls to State Highway Agency.

Construction

Year Built1977
MaterialPrestressed Concrete
Design TypeStringer/Multi-beam or Girder
OwnerState Highway Agency

Dimensions

Total Length60 ft (18.3 m)
Max Span9 ft (2.7 m)
Deck Width6 ft
Deck Area3,475 sq ft

Span dimensions affect structural design choices and load distribution. The deck area of 3,475 sq ft determines surface maintenance scope.

Classification

Route TypeInterstate
Route Number75
Lanes On Bridge3
Lanes Under Bridge

Status

Toll BridgeNo
Historical SignificanceNot eligible
Scour CriticalNo
Detour Length1 mi (2 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.

49,000

Avg Daily Traffic (2020)

Vehicles per day crossing this bridge

1%

Truck Traffic

Commercial vehicle percentage

118,095

Projected Future ADT

Estimated future demand

This bridge carries approximately 49,000 vehicles per day, translating to roughly 17,885,000 crossings annually. This moderate traffic level is typical for regional connectors.

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 118,095 vehicles daily, a 141% 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

2.8 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 2.8 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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35.163056, -85.171944

Identification

Structure Number000000001500860
NBI IDGA-000000001500860
State FIPS13
County FIPS015

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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.

I-75 (SBL) over ETOWAH RIVER | Georgia