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Preserving Historic Highway Bridges

To discuss four proven methods of preserving historic highway bridges: rehabilitating consistent with Secretary of the Interior’s Standards; rehabilitating not consistent with Standards; bypassing with new bridge and rehabilitating historic bridge for non-vehicular uses; moving old bridge to new location for non-vehicular uses. The panel will include at least three members: Stephen Mikesell, who has nearly 30 years’ experience working with historic highway bridges; Kitty Henderson, director of Historic Bridge Foundation, and who brings national perspective to the issue; Michael Kirn, Public Works Director, Calistoga, who led rehabilitation of the Healdsburg Bridge. The presentations will explore advantages and disadvantages of each of the four approaches, with California case studies. Case studies may include:
  • Rehabilitation meeting Standards: Healdsburg Bridge, Sonoma County.
  • Rehabilitation not meeting Standards: First Street Bridge, Los Angeles. La Loma Bridge, Pasadena.
  • Bypass and preserve: Guerneville Bridge, Sonoma County.
  • Moving the bridge to new location: Will likely use a non-California example as this approach is quite popular outside California and rarely used in this state.
The panel will discuss general problems associated with each approach, focusing on safety and funding issues that are unique to historic bridge projects. The panel will invite questions and comments from attendees.


  • Stephen Mikesell, Owner, Mikesell Historical Consulting
  • Kitty Henderson, Executive Director, Historic Bridge Foundation
  • Mike Kirn, Public Works Director, City of Calistoga.

Documents & Downloads

Preserving Historic Highway Bridges - Powerpoint

Continuing Education

  • Building Science and Performance
  • Design and Design Services
  • Legal
  • Materials and Methods
  • Project Types
  • Hazards
  • History
  • Infrastructure
  • Streets
  • Transportation
  • Urban Design
  • Historic Preservation
  • Project Management
  • Transportation
  • Urban Planning