How was the new bridge selected and what type of bridge is being proposed for the replacement bridge?

The Project Development and Environment (PD&E) Study considered several alternatives, including low and mid-level movable bridges and a fixed high-level bridge. These bridge types were analyzed with several horizontal alignment options. Based on the PD&E Study, the preferred alternative is a mid-level movable bridge and was finalized upon receipt of Location and Design Concept Acceptance (LDCA) by the Federal Highway Administration in March 2019. The new bridge will be a twin double leaf bascule bridge similar to the existing bridge.

Side View of Bridge

Will there be improvements to navigation through the channel?

Navigation clearances of the new bridge at the main channel will be 125 ft horizontal (existing is 90 ft) and 38 ft vertical (existing is 21 ft). The increase in vertical clearance will reduce the current number of required bridge openings by 44%.

What is the approach to construction and how will it affect vehicular and boat traffic?

There are three methods to replace a bridge such as the SR 5/US-1 Federal Highway Bridge over the Loxahatchee River/Atlantic Intracoastal Waterway.

1. Build a temporary SR 5/US-1 bridge over the Loxahatchee River to use during demolition of the existing bridge and construction of the new bridge.

Right-of-way constraints prohibit the use of a temporary bridge or partial construction of the new bridge off-line of the existing bridge.

2. Remove half of the existing bridge leaving one lane in each direction on the existing bridge while constructing half of the new bridge.

Maintaining traffic on half of the existing bridge during construction would require delicate removal of the other half of the existing bridge to construct the new bridge in phases. Under this phased construction approach, a 3-4 month complete shutdown of the bridge to vehicular traffic would be required during removal of half the bridge. During the removal of half the bridge there would be significant risk of damage to the other half of the bridge resulting in extended closures, unplanned prolonged detour, and construction delays.

3. The preferred construction method for this project is removing the existing bridge in its entirety and detour traffic to Alt A1A.

The project team developed a construction approach which constructs half of the new bridge during a 20-month detour. Following the 20-month detour, a higher bridge with bicycle and pedestrian facilities will be opened to one lane of traffic in either direction. The remaining half of the new bridge will be constructed in 15 months following the detour phase. The estimated total construction time of this method is 42 months. In summary, the preferred construction method provides the following benefits:

  • Avoids delicate removal of half existing bridge
  • Significantly reduces risk of existing bridge settlement and extended unplanned detours
  • First phase achieves new higher bridge with two lanes and 44% less openings
  • Expedites construction of bicycle and pedestrian facilities
  • Improves work zone mobility and safety
  • Reduces total construction duration by approximately 18 months

Will construction affect vehicular traffic?

There will be a complete shutdown of the bridge and a detour to Alternate A1A. Details on the detour route can be found on the main page of this site and by clicking the “Traffic Management and Intersection Improvements” tab on the left side of main page. The detour route will include intersection improvements at the following intersections to reduce impacts to traffic flow:

  • Alt A1A at Old Dixie Hwy
    • Shift the intersection to the southwest
    • Addition of signal
    • Lengthening of the northbound Alt A1A to northbound Old Dixie Hwy left turn lane
  • US 1 at SR 706 (Indiantown Rd)
    • Three left turning lanes from northbound US 1 to westbound SR 706 (two left turning lanes currently)
  • SR 706 (Indiantown Rd) at Alt A1A
    • Two left turning lanes from southbound Alt A1A to eastbound SR 706 (single left turning lane currently)
    • Two right turning lanes from westbound SR 706 to northbound Alt A1A
  • Alt A1A at US 1
    • Two right turning lanes from southbound US 1 to westbound Alt A1A

In addition, Intelligent Transportation System (ITS) will be placed along the entire detour route allowing users to make informed decisions through use of smart technology.

Will construction affect boat traffic?

Marine traffic will be maintained at all times.

What is the estimated timeframe of the detour phase?

The estimated timeframe of the 20-month detour phase is from Spring 2023 to the Fall of 2024. Refer to the estimated construction schedule on the main page of this website.

What is the estimated construction cost?

The estimated construction cost is $136 million

Will the project include landscape improvements?

A separate Landscaping project will be created after completion of the bridge replacement project.