I-75 N APPR over STRAITS OF MACKINAC

Map

Coordinates:
+45.84573, -84.72347
45°50'45" N, 84°43'24" W

Source: National Bridge Inventory. Information not verified; use at your own risk.

Name:	I-75 N APPR over STRAITS OF MACKINAC
Structure number:	000000000002457
Old structure number:	24186000000B020 `(from 1992 edition)`
Location:	N OF MACKINAC BR (CAUSWAY
Purpose:	Carries highway over waterway
Route classification:	Principal Arterial - Interstate (Rural) `[01]`
Tolls:	Yes `[1]`
Length of largest span:	29.9 ft. `[9.1 m]`
Total length:	89.9 ft. `[27.4 m]`
Roadway width between curbs:	56.1 ft. `[17.1 m]`
Deck width edge-to-edge:	59.4 ft. `[18.1 m]`
Vertical clearance below bridge:	6.6 ft. `[2.0 m]`
Owner:	State Toll Authority `[31]`
Year built:	1942
Year reconstructed:	1985
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:	Stringer/Multi-beam or girder `[02]`
Deck type:	Concrete Cast-in-Place `[1]`
Wearing surface:	Monolithic Concrete (concurrently placed with structural deck) `[1]`

Good/Fair/Poor Condition:	Good
Status:	Open, no restriction `[A]`
Average daily traffic:	11,076 `[as of 2007]`
Truck traffic:	7% of total traffic
Deck condition:	Very Good `[8 out of 9]`
Superstructure condition:	Good `[7 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 corrrective action `[3]`
Water adequacy appraisal:	Equal to present desirable criteria `[8]`
Roadway alignment appraisal:	Equal to present desirable criteria `[8]`
Channel protection:	Banks are protected or well vegetated. River control devices such as spur dikes and embankment protection are not required or are in a stable condition. `[8]`
Pier/abutment protection:	Navigation protection not required `[1]`
Scour condition:	Bridge foundations determined to be stable for the assessed or calculated scour condition. `[8]`
Sufficiency rating:	71.0

Date	Condition	Deck	Superstructure	Substructure	ADT	Suff. Rating
July 2018	Good	Very Good	Good	Good	11076	71.0
July 2017	Fair	Satisfactory	Satisfactory	Satisfactory	11076	71.0
July 2016	Good	Very Good	Good	Good	11076	71.0
July 2015	Good	Very Good	Good	Good	11076	71.0
July 2014	Good	Very Good	Good	Good	11076	71.0
August 2013	Good	Very Good	Good	Good	11076	71.0
July 2012	Good	Very Good	Good	Good	11076	71.0
July 2009	Good	Excellent	Good	Good	11076	71.0
July 2008	Good	Excellent	Good	Good	11076	71.0
August 2006	Good	Excellent	Good	Good	12000	71.0
August 2004	Good	Excellent	Good	Good	12000	71.0
July 2002	Good	Excellent	Excellent	Excellent	12000	68.0
August 1992	Good	Good	Good	Good	12000	73.0
August 1990	Good	Good	Good	Good	9200	70.0

Source: National Bridge Elements dataset, 2019 edition. This feature is experimental.

Element	Units	Quantity	1-Good	2-Fair	3-Poor	4-Serious
Superstructure
Steel Stringer	linear ft.	1,080	1,026	54	0	0
Steel Protective Coating	sq. ft.	7,560	3,780	3,780	0	0
Deck
Reinforced Concrete Deck	sq. ft.	5,265	4,739	526	0	0
Wearing Surfaces	sq. ft.	8,781	7,903	878	0	0
Substructure
Reinforced Concrete Abutment	linear ft.	117	117	0	0	0
Steel Pile	each	24	22	2	0	0
Steel Protective Coating	sq. ft.	777	699	78	0	0
Steel Pier Cap	linear ft.	117	105	12	0	0
Steel Protective Coating	sq. ft.	612	306	306	0	0
Bearings
Movable Bearing	each	24	24	0	0	0
Fixed Bearing	each	24	24	0	0	0
Bridge Rail
Steel or Aluminum Bridge Rail	linear ft.	132	132	0	0	0
Reinforced Concrete Bridge Rail	linear ft.	180	180	0	0	0