ST 1 A/LYNNWAY

over WATER SAUGUS RIVER

.3 MI DOWNSTREAM OF B&MRR, Essex County, Massachusetts

Condition

Poor

Year Built

1934

Daily Traffic

85,600

Length

127 ft

About This Bridge

ST 1 A/LYNNWAY carries traffic over WATER SAUGUS RIVER in Essex County, Massachusetts. Built in 1934, this structure is 92 years old, making it a historic structure that has served the community for generations. The bridge features steel construction with a movable - bascule design, a combination chosen by engineers to meet the specific requirements of this crossing.

Approximately 85,600 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 20% 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 127 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.

5

Deck Condition

Fair

5

Superstructure

Fair

4

Substructure

Poor

5

Channel & Protection

Fair

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 substructure rating of 4 reflects significant wear in piers, abutments, or foundations.

For a structure built in 1934, 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 7 miles, underscoring the importance of maintaining this crossing.

Bridge Details

Steel is the primary structural material, which influences maintenance requirements and expected lifespan. The movable - bascule 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 Built1934
Year Reconstructed1990
MaterialSteel
Design TypeMovable - Bascule
OwnerState Highway Agency

Dimensions

Total Length127 ft (38.8 m)
Max Span14 ft (4.1 m)
Deck Width7 ft
Deck Area8,491 sq ft

Span dimensions affect structural design choices and load distribution. The deck area of 8,491 sq ft determines surface maintenance scope.

Classification

Route TypeState Highway
Route Number1
Lanes On Bridge4
Lanes Under Bridge

Status

Toll BridgeNo
Historical SignificanceNot eligible
Scour CriticalNo
Detour Length7 mi (11 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.

85,600

Avg Daily Traffic (2022)

Vehicles per day crossing this bridge

20%

Truck Traffic

Commercial vehicle percentage

121,606

Projected Future ADT

Estimated future demand

This bridge carries approximately 85,600 vehicles per day, translating to roughly 31,244,000 crossings annually. This high volume places significant demands on the structure and necessitates frequent inspections.

Commercial trucks comprise 20% 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 121,606 vehicles daily, a 42% 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

4.1 tons

Maximum allowable load for special permits

Inventory Rating

2.4 tons

Load level for normal traffic

The operating rating of 4.1 tons represents the absolute maximum load this bridge can carry under controlled conditions with special permits. The inventory rating of 2.4 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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43.523333, -72.555556

Identification

Structure NumberL180154D7DOTNBI
NBI IDMA-L180154D7DOTNBI
State FIPS25
County FIPS009

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.

ST 1 A/LYNNWAY over WATER SAUGUS RIVER | Massachusetts