SR 18 over I 20


+32.29296, -90.26685
32°17'35" N, 90°16'01" W
Source: National Bridge Inventory
Information not verified. Use at your own risk.


Name:SR 18 over I 20
Structure number:31000180250556A
Location:SR 18 OVER I 20
Purpose:Carries highway over highway
Route classification:Other Principal Arterial (Urban) [14]
Length of largest span:102.0 ft. [31.1 m]
Total length:337.9 ft. [103.0 m]
Roadway width between curbs:48.6 ft. [14.8 m]
Deck width edge-to-edge:51.8 ft. [15.8 m]
Vertical clearance below bridge:15.7 ft. [4.8 m]
Skew angle:10°
Owner:State Highway Agency [01]
Year built:1969
Historic significance:Bridge is not eligible for the National Register of Historic Places [5]
Design load:MS 18+Mod / HS 20+Mod [6]
Number of main spans:4
Main spans material:Concrete continuous [2]
Main spans design:Box Beam or girders - Single or Spread [06]
Deck type:Concrete Cast-in-Place [1]

Latest Available Inspection: June 2014 

Status:Open, no restriction [A]
Average daily traffic:17,500 [as of 2012]
Truck traffic:3% of total traffic
Deck condition:Fair [5 out of 9]
Superstructure condition:Fair [5 out of 9]
Substructure condition:Very Good [8 out of 9]
Structural appraisal:Somewhat better than minimum adequacy to tolerate being left in place as is [5]
Deck geometry appraisal:Equal to present minimum criteria [6]
Underclearances appraisal:Somewhat better than minimum adequacy to tolerate being left in place as is [5]
Roadway alignment appraisal:Equal to present desirable criteria [8]
Scour condition:Bridge not over waterway. [N]
Operating rating:80.9 tons [73.5 metric tons]
Inventory rating:48.5 tons [44.1 metric tons]
Sufficiency rating:79.0

Previous Inspections 

DateSuff. ratingEvaluationDeckSuper.Sub.ADT
June 201479.0Not deficientFairFairVery Good17500
May 201279.1Not deficientFairFairVery Good16000
May 201079.1Not deficientFairFairVery Good15500
May 200891.2Not deficientSatisfactoryVery GoodVery Good15500
October 200691.2Not deficientSatisfactoryVery GoodVery Good15500
July 200493.3Not deficientGoodVery GoodVery Good13000
August 200293.3Not deficientGoodVery GoodVery Good14000
August 200093.4Not deficientGoodVery GoodVery Good12000
20000.0Not applicable---19500
July 199893.4Not deficientGoodVery GoodVery Good12000
September 199694.0Not deficientGoodVery GoodVery Good12000
December 199493.0Not deficientGoodVery GoodVery Good12000
February 199393.0Not deficientGoodVery GoodVery Good11580
March 199193.0Not deficientGoodVery GoodVery Good10720