MILLER ROAD
over CONRAIL
DEARBORN S/MICHIGAN, Wayne County, Michigan
Condition
PoorYear Built
1931
Daily Traffic
23,965
Length
146 ft
About This Bridge
MILLER ROAD carries traffic over CONRAIL in Wayne County, Michigan. Built in 1931, this structure is 95 years old, making it a historic structure that has served the community for generations. The bridge features steel construction with a stringer/multi-beam or girder design, a combination chosen by engineers to meet the specific requirements of this crossing.
Approximately 23,965 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 8% 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 146 feet, this structure falls within the typical range requiring standard inspection procedures conducted by certified bridge inspectors.
Steel bridges provide high strength-to-weight ratios, making them suitable for longer spans. However, they require ongoing protection against corrosion through painting or weathering steel designs. Inspectors pay close attention to connection points, fatigue cracking, and coating condition.
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.
Deck Condition
Poor
Superstructure
Critical
Substructure
Critical
Channel & Protection
N/A
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. The superstructure rating of 2 shows severe structural concerns in load-bearing elements. The substructure rating of 2 reflects critical foundation or pier problems.
For a structure built in 1931, 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
Steel 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
Dimensions
Span dimensions affect structural design choices and load distribution. The deck area of 9,748 sq ft determines surface maintenance scope.
Classification
Status
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.
23,965
Avg Daily Traffic (1995)
Vehicles per day crossing this bridge
8%
Truck Traffic
Commercial vehicle percentage
22,000
Projected Future ADT
Estimated future demand
This bridge carries approximately 23,965 vehicles per day, translating to roughly 8,747,225 crossings annually. This moderate traffic level is typical for regional connectors.
Commercial trucks comprise 8% 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 22,000 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
↓DecliningCondition has declined by 1.0 rating points since 2020
Data: 2020-2024 FHWA National Bridge Inventory
Location
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42.361111, -84.406667
Identification
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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.