HWY 91 N over BIG HOLE RIVER 041


+45.52664, -112.70197
45°31'36" N, 112°42'07" W


Source: National Bridge Inventory. Information not verified; use at your own risk.
Name:HWY 91 N over BIG HOLE RIVER 041
Structure number:L01311022+02001
Location:22M N DILLON
Purpose:Carries highway over waterway
Route classification:Local (Rural) [09]
Length of largest span:148.0 ft. [45.1 m]
Total length:232.0 ft. [70.7 m]
Roadway width between curbs:19.7 ft. [6.0 m]
Deck width edge-to-edge:21.3 ft. [6.5 m]
Vertical clearance above deck:16.1 ft. [4.9 m]
Owner:State Highway Agency [01]
Year built:1940
Historic significance:Bridge is not eligible for the National Register of Historic Places [5]
Design load:M 13.5 / H 15 [2]
Main span material:Steel [3]
Main span design:Truss - Thru [10]
Deck type:Concrete Cast-in-Place [1]
Wearing surface:Monolithic Concrete (concurrently placed with structural deck) [1]

Latest Available Inspection: July 2018

Good/Fair/Poor Condition:Poor
Status:Posted for load [P]
Average daily traffic:285 [as of 2017]
Deck condition:Fair [5 out of 9]
Superstructure condition:Poor [4 out of 9]
Substructure condition:Satisfactory [6 out of 9]
Structural appraisal:Basically intolerable requiring high priority of replacement [2]
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 minimum criteria [6]
Channel protection:Bank is beginning to slump. River control devices and embankment protection have widespread minor damage. There is minor stream bed movement evident. Debris is restricting the channel slightly. [6]
Scour condition:Bridge foundations determined to be stable for assessed or calculated scour condition. [5]
Sufficiency rating:29.9
Recommended work:Replacement of bridge or other structure because of substandard load carrying capacity or substantial bridge roadway geometry. [31]
Estimated cost of work:$678,000

Previous Inspections

DateConditionDeckSuperstructureSubstructureADTSuff. Rating
July 2018PoorFairPoorSatisfactory28529.9
August 2016FairSatisfactoryFairSatisfactory27039.9
June 2014FairSatisfactoryFairSatisfactory10045.4
June 2012FairSatisfactoryFairSatisfactory10046.4
June 2010FairSatisfactoryFairSatisfactory10046.4
July 2008PoorPoorFairSatisfactory10049.4
May 2006PoorPoorPoorFair10034.2
April 2004PoorPoorPoorFair10034.2
August 2001PoorPoorPoorFair10034.2
April 1999PoorPoorPoorFair10034.2
March 1997PoorPoorPoorFair10034.2
April 1995PoorPoorPoorFair3134.2
March 1993PoorPoorPoorFair25220.1
April 1991PoorPoorPoorFair9638.0

Element Data

Source: National Bridge Elements dataset, 2019 edition. This feature is experimental.
Reinforced Concrete Girder/Beamlinear ft.26211066860
Steel Stringerlinear ft.1,18409090275
Steel Protective Coatingsq. ft.4,5002,0252,025225225
Reinforced Concrete Decksq. ft.3,1652,1943506210
Wearing Surfacessq. ft.3,1653,1210440
Steel Trusslinear ft.2950282130
Steel Protective Coatingsq. ft.3,2501,3001,300325325
Steel Floor Beamlinear ft.20201315120
Steel Protective Coatingsq. ft.8643893894343
Reinforced Concrete Top Flangesq. ft.1,8061,4941751370
Wearing Surfacessq. ft.6465782660
Steel Gusset Plateeach3203200
Steel Protective Coatingsq. ft.16064641616
Reinforced Concrete Columneach40040
Reinforced Concrete Pier Walllinear ft.32151160
Reinforced Concrete Abutmentlinear ft.4031900
Timber Abutmentlinear ft.2002000
Reinforced Concrete Pier Caplinear ft.7267230
Movable Bearingeach20020
Steel Protective Coatingsq. ft.20110
Fixed Bearingeach20200
Steel Protective Coatingsq. ft.20011
Bridge Rail
Steel or Aluminum Bridge Raillinear ft.9364721862780
Steel Protective Coatingsq. ft.1,8721,176325139232