TR-82 (Daggert Roa

over East Johnson Creek

3 MI S MT. CARROLL, Carroll County, Illinois

Condition

Poor

Year Built

1916

Daily Traffic

25

Length

6 ft

About This Bridge

TR-82 (Daggert Roa carries traffic over East Johnson Creek in Carroll County, Illinois. Built in 1916, this structure is 110 years old, making it a historic structure that has served the community for generations. The bridge features wood or timber construction with a truss - thru design, a combination chosen by engineers to meet the specific requirements of this crossing.

Approximately 25 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.

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 6 feet, this is a shorter span typical of local road crossings, often carrying traffic over small streams, drainage channels, or other roadways.

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

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.

6

Deck Condition

Satisfactory

1

Superstructure

Imminent Failure

3

Substructure

Serious

7

Channel & Protection

Good

1

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 1 shows severe structural concerns in load-bearing elements. The substructure rating of 3 reflects serious deterioration in supports.

For a structure built in 1916, the current condition reflects the cumulative effects of age, traffic, and environmental exposure.

Bridge Details

Wood or Timber 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 Town/Township.

Construction

Year Built1916
MaterialWood or Timber
Design TypeTruss - Thru
OwnerTown/Township

Dimensions

Total Length6 ft (1.8 m)
Max Span5 ft (1.4 m)
Deck Width2 ft
Deck Area101 sq ft

Span dimensions affect structural design choices and load distribution. The deck area of 101 sq ft determines surface maintenance scope.

Classification

Route TypeCounty Road
Route Number0
Lanes On Bridge1
Lanes Under Bridge

Status

Toll BridgeNo
Historical SignificanceEligible for NRHP
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.

25

Avg Daily Traffic (2021)

Vehicles per day crossing this bridge

Truck Traffic

Commercial vehicle percentage

25

Projected Future ADT

Estimated future demand

This bridge carries approximately 25 vehicles per day, translating to roughly 9,125 crossings annually. Lower traffic volumes generally result in less structural wear over time.

Traffic projections estimate future volumes of 25 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

Maximum allowable load for special permits

Inventory Rating

Load level for normal traffic

5-Year Condition Trend

Declining

Condition has declined by 1.0 rating points since 2020

Data: 2020-2024 FHWA National Bridge Inventory

Location

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42.306667, -90.748333

Identification

Structure Number008370500000000
NBI IDIL-008370500000000
State FIPS17
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.

TR-82 (Daggert Roa over East Johnson Creek | Illinois