I 15

over Virgin River

09.6 mi E of Nevada, Mohave County, Arizona

Condition

Poor

Year Built

1964

Daily Traffic

27,997

Length

85 ft

About This Bridge

I 15 carries traffic over Virgin River in Mohave County, Arizona. Built in 1964, this structure is 62 years old, placing it among the older bridges still in active service. The bridge features steel continuous construction with a girder and floorbeam design, a combination chosen by engineers to meet the specific requirements of this crossing.

Approximately 27,997 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 26% of all crossings. This heavy commercial usage significantly impacts structural wear, as a single fully-loaded truck can cause as much deck wear as thousands of passenger vehicles. Transportation planners factor this into maintenance scheduling and budget allocation.

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 85 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.

5

Deck Condition

Fair

4

Superstructure

Poor

6

Substructure

Satisfactory

8

Channel & Protection

Very Good

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 superstructure rating of 4 shows advanced deterioration in beams or girders.

For a structure built in 1964, 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. If this bridge were closed, traffic would face a detour of approximately 99 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 girder and floorbeam 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 Built1964
Year Reconstructed1986
MaterialSteel Continuous
Design TypeGirder and Floorbeam
OwnerState Highway Agency

Dimensions

Total Length85 ft (25.8 m)
Max Span22 ft (6.6 m)
Deck Width7 ft
Deck Area5,281 sq ft

Span dimensions affect structural design choices and load distribution. The deck area of 5,281 sq ft determines surface maintenance scope.

Classification

Route TypeInterstate
Route Number15
Lanes On Bridge4
Lanes Under Bridge

Status

Toll BridgeNo
Historical SignificanceNot eligible
Scour Critical3
Detour Length99 mi (159 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.

27,997

Avg Daily Traffic (2018)

Vehicles per day crossing this bridge

26%

Truck Traffic

Commercial vehicle percentage

28,007

Projected Future ADT

Estimated future demand

This bridge carries approximately 27,997 vehicles per day, translating to roughly 10,218,905 crossings annually. This moderate traffic level is typical for regional connectors.

Commercial trucks comprise 26% 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. This high percentage of truck traffic may accelerate deterioration of deck surfaces and structural components.

Traffic projections estimate future volumes of 28,007 vehicles daily, a 0% 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

4.9 tons

Maximum allowable load for special permits

Inventory Rating

3.0 tons

Load level for normal traffic

The operating rating of 4.9 tons represents the absolute maximum load this bridge can carry under controlled conditions with special permits. The inventory rating of 3.0 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

Declining

Condition has declined by 1.0 rating points since 2020

Status Changes

  • Entered poor condition in 2021
  • Became structurally deficient in 2021
  • Exited poor condition in 2022
  • No longer structurally deficient as of 2022
  • Entered poor condition in 2023
  • Became structurally deficient in 2023

Data: 2020-2024 FHWA National Bridge Inventory

Location

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37.920000, -114.310000

Identification

Structure Number01089
NBI IDAZ-01089
State FIPS04
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 15 over Virgin River | Arizona