I-55

over MISS RIVER & CORD 312

ARKANSAS STATE LINE, Shelby County, Tennessee

Condition

Fair

Year Built

1949

Daily Traffic

69,044

Length

522 ft

About This Bridge

I-55 carries traffic over MISS RIVER & CORD 312 in Shelby County, Tennessee. Built in 1949, this structure is 77 years old, making it a historic structure that has served the community for generations. The bridge features steel continuous construction with a truss - thru design, a combination chosen by engineers to meet the specific requirements of this crossing.

Approximately 69,044 vehicles cross this bridge daily, making it a high-traffic corridor critical to regional transportation. Bridges carrying this volume require enhanced inspection schedules and proactive maintenance programs. Commercial trucks account for 8% 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 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 522 feet, this is a major span requiring specialized engineering expertise for inspection and maintenance. Longer bridges present unique challenges including thermal expansion, wind loads, and more complex structural analysis.

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

6

Deck Condition

Satisfactory

5

Superstructure

Fair

5

Substructure

Fair

5

Channel & Protection

Fair

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 1949, this condition level is expected given the bridge's age and usage patterns. High traffic volumes on a bridge in fair or poor condition typically elevate its priority for rehabilitation or replacement in state transportation planning.

Bridge Details

Steel Continuous is the primary structural material, which influences maintenance requirements and expected lifespan. The truss - thru 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 Built1949
MaterialSteel Continuous
Design TypeTruss - Thru
OwnerState Highway Agency

Dimensions

Total Length522 ft (159.2 m)
Max Span79 ft (24.1 m)
Deck Width6 ft
Deck Area26,581 sq ft

Span dimensions affect structural design choices and load distribution. The deck area of 26,581 sq ft determines surface maintenance scope.

Classification

Route TypeInterstate
Route Number55
Lanes On Bridge4
Lanes Under Bridge2

Status

Toll BridgeNo
Historical SignificanceOn National Register of Historic Places
Scour CriticalNo
Detour Length5 mi (8 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.

69,044

Avg Daily Traffic (2021)

Vehicles per day crossing this bridge

8%

Truck Traffic

Commercial vehicle percentage

67,200

Projected Future ADT

Estimated future demand

This bridge carries approximately 69,044 vehicles per day, translating to roughly 25,201,060 crossings annually. This high volume places significant demands on the structure and necessitates frequent inspections.

Commercial trucks comprise 8% 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 67,200 vehicles daily, a decrease 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

4.3 tons

Maximum allowable load for special permits

Inventory Rating

2.6 tons

Load level for normal traffic

The operating rating of 4.3 tons represents the absolute maximum load this bridge can carry under controlled conditions with special permits. The inventory rating of 2.6 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

Data: 2020-2024 FHWA National Bridge Inventory

Location

Loading map...

36.450000, -91.400278

Identification

Structure Number79I00550101
NBI IDTN-79I00550101
State FIPS47
County FIPS157

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.

I-55 over MISS RIVER & CORD 312 | Tennessee