Structure B162813EBDOTNBI · Suffolk County, MA

I 93 SB Bt 38-46 over Tr Orange Line

Carries I 93 SB Bt 38-46 over Tr Orange Line, .7 Mi N Of Jct I93&us1.

Overall conditionFair

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

How ratings work
Deck6/9 · Satisfactory
Superstructure6/9 · Satisfactory
Substructuresets the rating5/9 · Fair
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT652 FT OVERALL100 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9Superstructure 6/9Substructure 5/9 · sets the rating

652 ft end to end, longest span 82 ft: about 1.8 football fields. 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 girder bridge.

Built197056 years old
Length651.9 ft198.7 m
Daily traffic85,975counted 2023
Last inspectedNovember 2024every 24 months

Location

StateMassachusetts
CountySuffolk
Location.7 Mi N Of Jct I93&us1
CarriesI 93 SB Bt 38-46
CrossesTr Orange Line
Coordinates42.37536, -71.07302

Physical Characteristics

MaterialSteel
DesignGirder and Floorbeam
Total Length651.9 ft (198.7 m)
Max Span82.0 ft (25 m)
Deck Width68.9 ft (21 m)
Deck Area4172.7 sq m
Main Spans8
Year Built1970

Traffic

Avg Daily Traffic85,975 (2023)
Truck Traffic6%
Lanes On Bridge3

Inspection & Ownership

Last InspectionNovember 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure NumberB162813EBDOTNBI

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.

Nearby Bridges