BUFFALO BRIDGE RD

over FLATHEAD RIVER 084

10M W POLSON, Lake County, Montana

Condition

Good

Year Built

1993

Daily Traffic

100

Length

53 ft

About This Bridge

BUFFALO BRIDGE RD carries traffic over FLATHEAD RIVER 084 in Lake County, Montana. Built in 1993, this structure is 33 years old, built during a period of significant highway expansion. The bridge features steel continuous construction with a stringer/multi-beam or girder design, a combination chosen by engineers to meet the specific requirements of this crossing.

Approximately 100 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 3% 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 53 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

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 1993, maintaining good condition demonstrates effective maintenance practices. If this bridge were closed, traffic would face a detour of approximately 55 miles, underscoring the importance of maintaining this crossing.

Bridge Details

Steel Continuous 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 County Highway Agency.

Construction

Year Built1993
MaterialSteel Continuous
Design TypeStringer/Multi-beam or Girder
OwnerCounty Highway Agency

Dimensions

Total Length53 ft (16.1 m)
Max Span15 ft (4.5 m)
Deck Width2 ft
Deck Area901 sq ft

Span dimensions affect structural design choices and load distribution. The deck area of 901 sq ft determines surface maintenance scope.

Classification

Route TypeCounty Road
Route Number24002
Lanes On Bridge2
Lanes Under Bridge

Status

Toll BridgeNo
Historical SignificanceNot eligible
Scour Critical8
Detour Length55 mi (89 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.

100

Avg Daily Traffic (2024)

Vehicles per day crossing this bridge

3%

Truck Traffic

Commercial vehicle percentage

100

Projected Future ADT

Estimated future demand

This bridge carries approximately 100 vehicles per day, translating to roughly 36,500 crossings annually. Lower traffic volumes generally result in less structural wear over time.

Commercial trucks comprise 3% 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 100 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

3.7 tons

Maximum allowable load for special permits

Inventory Rating

2.2 tons

Load level for normal traffic

The operating rating of 3.7 tons represents the absolute maximum load this bridge can carry under controlled conditions with special permits. The inventory rating of 2.2 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

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49.171667, -115.592222

Identification

Structure NumberL24002008+00001
NBI IDMT-L24002008+00001
State FIPS30
County FIPS047

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.

BUFFALO BRIDGE RD over FLATHEAD RIVER 084 | Montana