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I-75 over STRAITS OF MACKINAC

Map

Coordinates:
+45.83691, -84.72488
45°50'13" N, 84°43'30" W

Facts

Source: National Bridge Inventory. Information not verified; use at your own risk.
Name:I-75 over STRAITS OF MACKINAC
Structure number:000000000002456
Old structure number:24186000000B010 (from 1992 edition)
Location:MACKINAW CITY-ST IGNACE
Purpose:Carries highway over waterway
Route classification:Principal Arterial - Interstate (Rural) [01]
Tolls:Yes [1]
Length of largest span:3801.0 ft. [1158.5 m]
Total length:19248.6 ft. [5866.7 m]
Roadway width between curbs:47.9 ft. [14.6 m]
Deck width edge-to-edge:53.8 ft. [16.4 m]
Vertical clearance below bridge:134.8 ft. [41.1 m]
Owner:State Toll Authority [31]
Year built:1957
Historic significance:Bridge is on the National Register of Historic Places [1]
Design load:MS 18 / HS 20 [5]
Number of main spans:3
Main spans material:Steel [3]
Main spans design:Suspension [13]
Deck type:Concrete Cast-in-Place [1]
Wearing surface:Bituminous [6]

Latest Available Inspection: July 2016

Good/Fair/Poor Condition:Fair
Status:Open, no restriction [A]
Average daily traffic:11,076 [as of 2007]
Truck traffic:7% of total traffic
Deck condition:Satisfactory [6 out of 9]
Superstructure condition:Very Good [8 out of 9]
Substructure condition:Good [7 out of 9]
Structural appraisal:Better than present minimum criteria [7]
Deck geometry appraisal:Basically intolerable requiring high priority of replacement [2]
Water adequacy appraisal:Superior to present desirable criteria [9]
Roadway alignment appraisal:Superior to present desirable criteria [9]
Channel protection:There are no noticeable or noteworthy deficiencies which affect the condition of the channel. [9]
Pier/abutment protection:Navigation protection not required [1]
Scour condition:Bridge foundations determined to be stable for the assessed or calculated scour condition. [8]
Operating rating:53.0 tons [48.2 metric tons]
Inventory rating:37.0 tons [33.6 metric tons]
Sufficiency rating:56.0

Previous Inspections

DateSuff. RatingConditionDeckSuperstructureSubstructureSD/FOADT
July 201656.0FairSatisfactoryVery GoodGoodFO11076
July 201556.0FairSatisfactoryVery GoodGoodFO11076
July 201456.0FairSatisfactoryVery GoodGoodFO11076
August 201356.0FairSatisfactoryVery GoodGoodFO11076
July 201256.0FairSatisfactoryVery GoodGoodFO11076
July 200956.0FairSatisfactoryVery GoodGoodFO11076
July 200856.0FairSatisfactoryVery GoodGoodFO11076
August 200656.0FairSatisfactoryVery GoodGoodFO12398
August 200456.0GoodVery GoodExcellentGoodFO12000
July 200253.0GoodVery GoodExcellentGoodFO12000
August 199053.0GoodGoodGoodGoodFO12000

Element Data

Source: National Bridge Elements dataset, 2016 edition. This feature is experimental.
ElementUnitsQuantity1. Good2. Fair3. Poor4. Serious
Superstructure
Steel Stringerlinear ft.104,845102,2652,529510
Steel Protective Coatingsq. ft.960,724921,04424,68013,3001,700
Deck
Reinforced Concrete Decksq. ft.525,337525,337000
Wearing Surfacessq. ft.504,836504,831050
Superstructure
Steel Trusslinear ft.60,87560,170655500
Steel Protective Coatingsq. ft.1,990,0001,989,295655500
Steel Main Cablelinear ft.16,72816,728000
Steel Protective Coatingsq. ft.107,669107,669000
Steel Floor Beamlinear ft.18,19817,561612250
Steel Protective Coatingsq. ft.183,860167,25510,1056,000500
Steel Gusset Plateeach4,4564,448800
Steel Protective Coatingsq. ft.55,84654,046400600800
Substructure
Reinforced Concrete Columneach4439500
Steel Column Tower/Trestlelinear ft.1,0461,046000
Reinforced Concrete Pier Walllinear ft.6536282500
Other Material Abutmentlinear ft.50035150
Deck
Open Grid Decksq. ft.162,8000162,80000
Steel Protective Coatingsq. ft.162,8000162,80000
Concrete Filled Grid Decksq. ft.177,6000177,60000
Wearing Surfacessq. ft.177,600177,600000
Joints
Strip Seal Jointlinear ft.10,3621,3904,5624,34961
Pourable Jointlinear ft.6001293472599
Assembly without Seal Jointlinear ft.871627216280
Bearings
Movable Bearingeach1,8251,520286190
Fixed Bearingeach2,1041,928165110