Latest FDOT Inspections of Miami Beach Bridges

Susan Askew
Susan Askew

Latest FDOT Inspections of Miami Beach Bridges:

Four bridges with sufficiency ratings below 70% need repairs

In its biannual bridge report, the Florida Department of Transportation (FDOT) identified four bridges in Miami Beach with sufficiency ratings “that are below the City threshold of 70%,” according to a memo to City Commission from City Manager Jimmy Morales.
 
The memo is a transmission note for next week’s Commission meeting in which the Administration is asking the item be referred to the Finance Committee for discussion of funding repairs. A chart attached to the memo lists 24 City bridges along with their sufficiency ratings which could range from 0 to 100. 
 
Miami Beach Director of Communications Tonya Daniels said in an email sufficiency ratings are used by FDOT “to measure the structural adequacy and safety, serviceability and functionally and level of service for public use.”
 
“70% or above sufficiency rating means that the bridge is in good condition, no action is required by the City,” according to Daniels. (The photo above is of the bridge to Palm Island which has a rating of 78.0.)
 
She adds, “The needed repairs on a bridge at [these] ratings are not affecting the structural capacity of the bridge to carry loads but they require attention to extend the service life of the bridge. Some of the bridge elements shows some deterioration, discoloration, superficial cracking or surface evidence of reinforcing bars corrosion.”
 
Of the four bridges rated below 70%, the 77th Street Bridge over Biscayne Point Canal rates a 45.1. A note indicates there were some repairs completed on August 15, 2015 though they are not detailed.
 
The 73rd Street Bridge over Tatum Waterway rated a 61.0 and was deemed functionally obsolete.
 
The other two are the 77th Street Bridge over Tatum Waterway (62.7) which had some undefined repairs completed in January of 2007 and the Henedon Avenue Bridge over Biscayne Point Canal (62.0) which had undefined work completed in September of 2010.
 
As to the cost, Daniels said, “We estimate that the needed repairs could vary between $100-500K per bridge under the 70% sufficiency rating parameter.”
 
Currently there is no money budgeted for the repairs. Daniels said, “[W]e are currently looking into different funding sources but it will for preventative maintenance.”
 
Further details are provided in an FDOT “Bridge Condition Terminology” document: “The ‘sufficiency rating’ is a tool that is used to help determine whether a bridge that is structurally deficient or functionally obsolete should be repaired or just replaced. The sufficiency rating considers a number of factors, only about half of which relate to the condition of the bridge itself. The sufficiency ratings for bridges are part of a formula used by the Federal Highway Administration (FHWA) when it allocates federal funds to the states for bridge replacement.” [Emphasis in the FDOT document.]
 
In a 2006 PowerPoint presentation by Richard Kerr, an engineer with FDOT, the formula for the sufficiency scale is described as follows: Structural Adequacy and Safety 55%, Serviceability 30%, Essentiality for Public Use 15%, and an undefined category of Special Reductions (up to 13%). Kerr’s presentation says that under FHWA definitions, “If a Bridge is Structurally Deficient or Functionally Obsolete with a Sufficiency Rating of less than 50 it qualifies for replacement using federal bridge funds.” 
 
Functionally obsolete is defined in a 2015 presentation by Kerr as bridges that may have narrow lanes, a low underclearance, an approach roadway that requires a “major traffic slowdown to cross the bridge,” a “very low inventory load rating and bridge needs repair,” and/or “occasional flooding that causes traffic delays.” 

According to BridgeReports.com (yeah, we know but if we didn’t find it, who would?), quoting National Bridge Inventory data:
 
77th Street Bridge over Biscayne Point Canal was built in 1955. At its last inspection in April 2016, its condition was rated as Fair (on a scale of Good/Fair/Poor). Its deck condition was listed as Fair [5 out of 9]; Superstructure condition, Fair [5 out of 9]; and Substructure condition, Fair [5 out of 9]. According to the structural appraisal, it is “Somewhat better than minimum adequacy to tolerate being left in place as is and its deck geometry appraisal indicated it “Meets minimum tolerable limits to be left in place as is.” According to Kerr's 2015 presentation, ratings from 5 to 9 are NOT structurally deficient. Anything below a 5 is structurally deficient.
 
73rd Street Bridge over Tatum Waterway was built in 1989. At its last inspection in April 2016, its condition was rated as Good (on a scale of Good/Fair/Poor). Its deck condition was rated as Good [7 out of 9]; Superstructure condition, Good [7 out of 9]; and its Substructure condition, Good [7 out of 9]. While its structural appraisal was “Better than present minimum criteria,” it’s deck geometry appraisal indicated it was “Basically intolerable requiring high priority of replacement.” 
 
77th Street Bridge over Tatum Waterway was built in 1955. At its last inspection in April 2016, its overall condition was listed as Fair (on a scale of Good/Fair/Poor). Its deck condition was listed as Fair [5 out of 9]; Superstructure condition, Fair [5 out of 9]; and its Substructure condition was Fair [5 out of 9]. Comment under structural appraisal: “Somewhat better than minimum adequacy to tolerate being left in place as is. Comment on its deck geometry appraisal: Basically intolerable requiring high priority of replacement.
 
Henedon Avenue Bridge was built in 1950. From the October 2016 inspection, the bridge overall was listed in Good condition (on a scale of Good/Fair/Poor). Its deck condition was listed as Very Good [8 out of 9], Superstructure condition Very Good [8 out of 9] and its substructure condition was Good [7 out of 9]. The comment from the structural appraisal is that it “Meets minimum tolerable limits to be left in place as is” and from the deck geometry appraisal, it “Meets minimum tolerable limits to be left in place as is.”

Photo: Shutterstock.com

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