Structure W380362HXDOTNBI · Middlesex County, MA

I 93 NB over Rr Mbta/bmrr

Carries I 93 NB over Rr Mbta/bmrr, 0.8 Mi N Of St-125.

Overall conditionFair

Set by its lowest-rated component: Deck at 5 of 9.

How ratings work
Decksets the rating5/9 · Fair
Superstructure6/9 · Satisfactory
Substructure6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT76 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 5/9 · sets the ratingSuperstructure 6/9Substructure 6/9

76 ft end to end. Lengths and the car on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a multi-beam bridge.

Built195967 years old
Length76.1 ft23.2 m
Daily traffic73,300counted 2016
Last inspectedMarch 2024every 24 months

Location

StateMassachusetts
CountyMiddlesex
Location0.8 Mi N Of St-125
CarriesI 93 NB
CrossesRr Mbta/bmrr
Coordinates42.59353, -71.16621

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length76.1 ft (23.2 m)
Max Span71.9 ft (21.9 m)
Deck Width69.2 ft (21.1 m)
Deck Area489.5 sq m
Main Spans1
Year Built1959

Traffic

Avg Daily Traffic73,300 (2016)
Truck Traffic10%
Lanes On Bridge4

Inspection & Ownership

Last InspectionMarch 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure NumberW380362HXDOTNBI

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

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