Structure N150182XKDOTNBI · Essex County, MA

I 495 NB Ramp N over Comb Sutton ST & Mbta

Carries I 495 NB Ramp N over Comb Sutton ST & Mbta, Next To I495.

Overall conditionPoor

Set by its lowest-rated component: Superstructure at 4 of 9.

How ratings work
Deck6/9 · Satisfactory
Superstructuresets the rating4/9 · Poor
Substructure5/9 · Fair
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT385 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9Superstructure 4/9 · sets the ratingSubstructure 5/9

385 ft end to end, longest span 111 ft: about 5 semi-trucks nose to tail. Lengths and the semi-truck 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.

Built196363 years old
Length384.8 ft117.3 m
Daily traffic13,684counted 2023
Last inspectedMay 2024every 12 months

Location

StateMassachusetts
CountyEssex
LocationNext To I495
CarriesI 495 NB Ramp N
CrossesComb Sutton ST & Mbta
Coordinates42.70333, -71.13957

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length384.8 ft (117.3 m)
Max Span110.9 ft (33.8 m)
Deck Width34.1 ft (10.4 m)
Deck Area1219.9 sq m
Main Spans6
Year Built1963

Traffic

Avg Daily Traffic13,684 (2023)
Truck Traffic4%
Lanes On Bridge2
Lanes Under Bridge2

Inspection & Ownership

Last InspectionMay 2024
Inspection FrequencyEvery 12 months
OwnerState Highway Agency
Historical SignificanceBridge is possibly eligible (requires evaluation)
Scour CriticalNot applicable
Structure NumberN150182XKDOTNBI

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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