Eugene C' Figg Jr' Medal For Signature Bridges

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What Makes a Bridge Historic?

• Anything over 50 years old
• Important in the areas of engineering, history,
  transportation
• Important to the surrounding community
• All historic bridges are by definition important
  to their surrounding communities
• Also an important means of commerce and travel

Royal Park Bridge
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Royal Park Bridge, Palm Beach County, FL
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Evolution of Royal Park Bridge
1950s
1990s
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Royal Park Bridge PDE Study Alternatives
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Royal Park Bridge, 2005
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Royal Park Bridge, 2005
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Royal Park Bridge2007
2007 International Bridge ConferenceEugene C.
Figg Jr. Medal for Signature Bridgesawarded to
the Florida Department of Transportation for
theROYAL PARK BRIDGE REPLACEMENT for a single
recent outstanding achievement in bridge
engineering that, through vision and innovation,
provides an icon to the community for which it
was designed.
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Flagler Memorial Bridge, Palm Beach County, FL
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Flagler Memorial Bridge,1930s
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Flagler Memorial Bridge, 1950s
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Flagler Memorial Bridge, 2007
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Flagler Memorial Bridge, 2007
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Flagler Memorial Bridge, 2007
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Existing Bridge Structurally Deficient
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Existing Bridge Structurally Deficient
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Existing BridgeConditions
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Existing Bridge Conditions
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Existing Bridge Conditions
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Existing Bridge Functionally Obsolete
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Planning for the New FlaglerMemorial Bridge
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Alternative 1A and 2A(at grade)
Alternative 1A and 2A WITH FLAGLER DRIVE AT GRADE
CONCEPT (same location as existing bridge)
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Alternative 1B and 2B(with ramps)
Alternative 1B and 2B BRIDGE OVER FLAGLER DRIVE
WITH RAMPS TO FLAGLER DRIVE (new bridge to the
south of the existing bridge)
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Alternative 1B and 2B(at grade)
Alternative 1B and 2B WITH FLAGLER DRIVE AT GRADE
CONCEPT (new bridge to the south of the existing
bridge)
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Some Proposed Improvements
Flagler Drive looking North at existing Flagler
Memorial Bridge
Proposed At-Grade Intersection with Flagler
Drive
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Some Proposed Improvements
Flagler Drive looking South at existing Flagler
Memorial Bridge
Proposed At-Grade Intersection with Flagler Drive
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When Should a Historic Bridge Be Rehabilitated?

• When a communitys desire to retain existing
  bridge is extremely high
• If at least 15 of existing bridge can be
  retained
• If permitting process for new bridge is complex
• If bridge can be improved to an acceptable level
  without adversely affecting its historic
  significance

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Disadvantages of Rehabilitation

• Navigable waterway under bridge is not improved
• Lane widths, sidewalk bicycle lane
  accommodations typically remain unchanged or less
  than desired
• No opportunity to architecturally enhance bridge
  appearance

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When Should a Historic Bascule Bridge Be
Replaced?

• Low structural sufficiency is key reason
• Bridge maintenance report rates structural
  components on a scale of 1 through 10
• If any component rates lower than 5, further
  evaluation is required
• Functional obsolescence is second reason
• Doesnt meet current design standards
• Heavy traffic load
• High incidence of crashes

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When Should a Historic Bascule Bridge Be
Replaced?

• They are difficult to maintain
• Design life is typically 50 years
• Frequently built with combinations of wood,
  concrete, and/or steel piles
• Superstructures are typically reinforced concrete
• Salt environments are hostile to concrete and
  steel
• Bascule bridges are usually low further
  exposing bridge members to harsh salt and spray
• Modern structures resist effects of salt
• Design life is typically 75 years
• Concrete is treated with special hardeners

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75-Year Design Life

• Designed for ship impacts
• Designed for bridge scour
• Superstructure can be widened as much as necessary

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Few Written Protocols or Guidelines

• Have all possibilities been considered to make
  bridge safe and maintain its historical
  significance?
• Rehabilitation when is and isnt it practical?
• Historic preservation at what point does
  rehabilitation adversely affect a bridge?

as reported in AASHTOs Guidelines for
Historic Bridge Rehabilitation and Replacement,
2007
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Engineering Judgment BalancedWith Historic
Preservation

• How to address deficiencies load capacity,
  geometry, safety, environmental issues
• How to preserve NRHP bridges
• Balanced decision making is key

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New Federal Replacement Fund Guidelines Announced

• Federal Highway Administration (FHWA) officials
  conceded at a national conference that Bridge
  Replacement Fund guidelines are actually at odds
  with the goal of preserving historic bridges.
  Current guidelines provide 80 of the cost of
  building new bridges, but preclude using these
  monies to restore historic bridges to their fully
  functional condition. FHWA is conducting an
  internal review of this process to address the
  stated goal of encouraging bridge preservation.