CLARA BARTON PARKW

over CLARA BARTON PARKWAY (SB

0.1 MILES WEST OF MACARTH, Montgomery County, Maryland

Condition

Poor

Year Built

1959

Daily Traffic

40,057

Length

141 ft

About This Bridge

CLARA BARTON PARKW carries traffic over CLARA BARTON PARKWAY (SB in Montgomery County, Maryland. Built in 1959, this structure is 67 years old, placing it among the older bridges still in active service. The bridge features concrete construction with a slab design, a combination chosen by engineers to meet the specific requirements of this crossing.

Approximately 40,057 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 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 141 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.

4

Deck Condition

Poor

5

Superstructure

Fair

6

Substructure

Satisfactory

Channel & Protection

N/A

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 deck rating of 4 indicates advanced deterioration affecting the driving surface.

For a structure built in 1959, the current condition reflects the cumulative effects of age, traffic, and environmental exposure. 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

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 National Park Service.

Construction

Year Built1959
Year Reconstructed1995
MaterialConcrete
Design TypeSlab
OwnerNational Park Service

Dimensions

Total Length141 ft (43.0 m)
Max Span141 ft (43.0 m)
Deck Width2 ft
Deck Area1,933 sq ft

Span dimensions affect structural design choices and load distribution. The deck area of 1,933 sq ft determines surface maintenance scope.

Classification

Route TypeFederal Lands
Route Number6
Lanes On Bridge2
Lanes Under Bridge2

Status

Toll BridgeNo
Historical SignificanceNot eligible
Scour CriticalN
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.

40,057

Avg Daily Traffic (2023)

Vehicles per day crossing this bridge

1%

Truck Traffic

Commercial vehicle percentage

54,990

Projected Future ADT

Estimated future demand

This bridge carries approximately 40,057 vehicles per day, translating to roughly 14,620,805 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 54,990 vehicles daily, a 37% 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

10.0 tons

Maximum allowable load for special permits

Inventory Rating

10.0 tons

Load level for normal traffic

The operating rating of 10.0 tons represents the absolute maximum load this bridge can carry under controlled conditions with special permits. The inventory rating of 10.0 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

Status Changes

  • Exited poor condition in 2023
  • No longer structurally deficient as of 2023
  • Entered poor condition in 2024
  • Became structurally deficient in 2024

Data: 2020-2024 FHWA National Bridge Inventory

Location

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40.319444, -77.497222

Identification

Structure Number3300044P0000000
NBI IDMD-3300044P0000000
State FIPS24
County FIPS031

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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.

CLARA BARTON PARKW over CLARA BARTON PARKWAY (SB | Maryland