Loading structural data... this is riveting stuff.
Loading structural data... this is riveting stuff.
Almost there! Just bridging the gap...
over US 1 NB/BIG MYSTIC LOWR
BIG MYSTIC UPPER
Parametric wireframe generated from real NBI dimensions. Drag to rotate, scroll to zoom.
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This bridge has a Fair overall condition rating of 5 out of 9. While it is not classified as structurally deficient, it shows some deterioration that is being monitored.
The bridge carries 41,655 vehicles per day and is 76 years old.
Its sufficiency rating of 56.0 places it below the national average of 63.6.
The NBI records a navigation clearance of 16 feet — the minimum vertical space below the bridge deck. The total height of the bridge structure (including towers, railings, and superstructure) may be higher.
For travelers with bridge anxiety
This bridge may cause some awareness for travelers with bridge anxiety, but has manageable characteristics.
This bridge is 1524 feet long — a moderate crossing, about 30 seconds.
A truss bridge — the steel framework can provide a sense of enclosure.
About 16 feet above ground — standard overpass height.
About 41,655 vehicles cross daily — moderate traffic, some congestion possible.
The deck is 42 feet wide with 2-3 lanes — moderate width.
This bridge crosses over land, not water — no water views below.
This comfort score is designed to help individuals with bridge anxiety plan their travel. All bridges in the National Bridge Inventory are regularly inspected and deemed safe for travel. This is not medical advice — if you experience severe anxiety, please consult a healthcare professional.
Year Built
1950
76 years old
Structure Type
Steel (Continuous) Truss (Thru)
Total Length
1,524 ft
464.5 m
Deck Width
42 ft
12.7 m
Spans
3
sections between supports
Max Span
801 ft
longest unsupported section (244.1 m)
Traffic Lanes
3 lanes
One-way traffic
Clearance Below
16 ft
navigation clearance under deck
Clearance height compared to familiar objects
Height shown is the navigation clearance below the bridge deck. The total height of the bridge structure (including towers and superstructure) may be higher.
Daily Traffic
41,655vehicles/day
42.38510°N, 71.04729°W
Steel (Continuous) Truss (Thru)
A steel truss bridge uses a framework of interconnected triangular elements. The geometric rigidity of triangles makes this design extremely efficient at distributing loads.
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Data from the National Bridge Inventory (NBI), maintained by the Federal Highway Administration (FHWA).
Data year: 2025. Conditions may have changed since the last inspection.
This information is provided for educational and informational purposes only. It should not be used as the sole basis for any decisions related to bridge safety or transportation planning. Always consult official sources and local authorities for the most current data.