I-15 (SR-15) SBL

over 900 SOUTH STREET & U.P.

550 WEST 900 SO.ST. SLC, Salt Lake County, Utah

Condition

Fair

Year Built

2000

Daily Traffic

252,426

Length

57 ft

About This Bridge

I-15 (SR-15) SBL carries traffic over 900 SOUTH STREET & U.P. in Salt Lake County, Utah. Built in 2000, this structure is 26 years old, representing modern engineering and construction standards. 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 252,426 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 7% 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 57 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

6

Deck Condition

Satisfactory

7

Superstructure

Good

7

Substructure

Good

Channel & Protection

N/A

6

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 6 indicates satisfactory condition with minor section loss or deterioration.

For a structure built in 2000, this condition level is expected given the bridge's age and usage patterns.

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 State Highway Agency.

Construction

Year Built2000
MaterialSteel Continuous
Design TypeStringer/Multi-beam or Girder
OwnerState Highway Agency

Dimensions

Total Length57 ft (17.3 m)
Max Span22 ft (6.8 m)
Deck Width11 ft
Deck Area5,937 sq ft

Span dimensions affect structural design choices and load distribution. The deck area of 5,937 sq ft determines surface maintenance scope.

Classification

Route TypeInterstate
Route Number15
Lanes On Bridge7
Lanes Under Bridge4

Status

Toll BridgeNo
Historical SignificanceNot eligible
Scour CriticalN
Detour Length1 mi (1 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.

252,426

Avg Daily Traffic (2023)

Vehicles per day crossing this bridge

7%

Truck Traffic

Commercial vehicle percentage

302,911

Projected Future ADT

Estimated future demand

This bridge carries approximately 252,426 vehicles per day, translating to roughly 92,135,490 crossings annually. This high volume places significant demands on the structure and necessitates frequent inspections.

Commercial trucks comprise 7% 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 302,911 vehicles daily, a 20% 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

5.8 tons

Maximum allowable load for special permits

Inventory Rating

3.3 tons

Load level for normal traffic

The operating rating of 5.8 tons represents the absolute maximum load this bridge can carry under controlled conditions with special permits. The inventory rating of 3.3 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

Data: 2020-2024 FHWA National Bridge Inventory

Location

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40.776944, -112.925278

Identification

Structure Number3C 868S
NBI IDUT-3C 868S
State FIPS49
County FIPS035

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-15 (SR-15) SBL over 900 SOUTH STREET & U.P., Utah — Bridge Condition | BridgeReport.org | BridgeReport.org