Summary
Needs Assessment
Two bridges connect SR 80
(Southern Boulevard) in the City of
(ICWW) and the Lake Worth
Lagoon. The main bridge is a movable or bascule
bridge which currently provides 10 feet of vertical
clearance and 80 feet of horizontal clearance. U.S.
Coast Guard required clearances at this site are 21 feet
vertical and 125 feet horizontal for a bascule bridge.
The second and easternmost bridge, referred to as the
tidal relief bridge, is a low level fixed bridge that
spans a narrow section of open water along the eastern
shore of the lagoon. SR 80 is a designated
emergency evacuation route from the barrier island
communities to the mainland.
Both bridges were constructed in 1950. Despite continued efforts to repair the existing bridges, engineering studies have determined that the bridge structures are deteriorating and are in need of major repair or replacement. In addition, some elements of the
bridge are not constructed to
current design standards. For example, the
existing sidewalks are only 3.5 feet wide; sidewalks
must be a minimum of six feet under current standards.
In addition, the US Coast Guard establishes requirements
for vertical and horizontal clearances for bridges that
cross the ICWW. The existing bascule bridge
clearances are less than these requirements.
The movable bridge has a
sufficiency rating of 48.9; the tidal relief bridge has
a sufficiency rating of 36.3. Bridges are assigned
a sufficiency rating based on their overall condition.
Deterioration of the bridge and an assessment of the
features on the bridge that may affect safety are
considered when determining the rating.
Sufficiency ratings range from 0 to 100, where 100 is
excellent and 0 is extremely poor. Bridges
with a sufficiency rating of less than 50 are generally
eligible for replacement with federal funds.
Planning, Design and
Construction
Project Overview
The Florida Department of Transportation (FDOT) District Four performed a PD&E study to evaluate alternatives to rehabilitate or replace both bridges. The limits of the PD&E study extended from SR-805 (South Dixie Highway) in the City of West Palm Beach on the mainland to SR A1A (South Ocean Boulevard) in the Town of Palm Beach on the barrier island. The length of the project is approximately 1 mile. Alternative 2 was chosen as
the recommended alternative and LDCA was granted by FHWA on May 12, 2009.
The existing bridges provide
one 12-foot travel lane in each direction, two feet of
buffer between the edge of the driving lane and the face
of the sidewalk, and 3.5 foot-wide sidewalks exists on
both sides of the bridge. Based on the traffic
analysis of the existing roadway network and the traffic
projections made for the year 2032 no additional travel
lanes will be proposed for the replacement bridges.
However, widening of the existing bridge will be
required to meet current design and safety standards.
Finance
Federal and state funding is allocated for future phases of the project, including Design and Construction. The current construction costs estimate for the Preferred Alternative, which consists of construction of a new 21-foot high movable bridge over the Intracoastal Waterway, and a new fixed bridge over the Lake Worth Lagoon is approximately
67 million dollars.
Project Status
A design-build request for proposal package and conceptual plans are currently being developed by FDOT. The design-build phase of this project is scheduled to start in June 2013.
