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The Florida Keys are connected by 42 different bridges. Building these structures requires some of the most demanding construction work in the country, but that essential effort makes the Keys accessible to residents, businesses, and tourists alike.
Charley Toppino & Sons has been working in the Florida Keys for over a century. As one of the region’s most experienced bridge construction companies, we’ve built and maintained infrastructure from Key Largo to Key West. In this blog, we’ll walk through how causeways and overpasses are built, what makes their construction uniquely challenging, and why Charley Toppino & Sons is the best choice for highway bridge construction.
Highway bridge construction is among the most complex construction undertakings. It requires structural coordination, specialized equipment, and the ability to build safely over or near water, active traffic, and — in the case of the Keys — protected marine ecosystems. The process of building a bridge is also rarely a single contractor’s work, which is where the relationship between builder and engineer becomes foundational.
Charley Toppino & Sons operates as a contractor. We execute our work to engineered specifications and work closely with engineering firms to ensure designs work in the field. A design that looks good on paper can sometimes create jobsite challenges, and our expertise in flagging those issues before breaking ground adds value to every project.
Here’s how to build a bridge, from the first site assessment to the final DOT inspection.
Before any groundbreaking, the site must undergo soil testing, environmental surveys, and permitting. In the Florida Keys, that permitting process is more complex than in the rest of the country. Bridges here span wetlands, flood zones, and protected marine ecosystems, including the NOAA Florida Keys National Marine Sanctuary: one of the country’s most protected marine environments. Seagrass beds, coral reefs, and shallow tidal flats must all be accounted for before a single pile goes into the ground.
Everything starts with the foundation. For highway bridge construction, this usually involves driving piles or installing drilled shafts deep into the ground or seabed. In marine settings, crews use special equipment and work closely with waterway traffic and environmental monitors. A solid foundation is key to making sure a structure lasts for decades.
After the foundation is set, the next step is building the substructure. This includes the piers, columns, and abutments that hold up the deck. In places like the Florida Keys, where saltwater is a constant factor, builders always use corrosion-resistant bridge construction materials and special admixtures for every substructure pour. Salt air and tides can quickly wear down steel inside the concrete, so choosing the right materials from the beginning is key to making a structure last.
The superstructure is the part that spans between supports and carries the load. Bridge type matters here; for example, a beam uses horizontal girders, a truss distributes the load through a steel framework of triangles, and a segmental is built from precast concrete pieces joined end to end.
The deck, where vehicles drive, is usually made of poured concrete or precast panels. Bridge construction materials are chosen based on span length, load, and bridge design. In the Keys, we also have to select materials capable of withstanding the harsh, salty environment.
The final phase covers everything that makes the bridge functional and safe for traffic: roadway surfacing, guardrails, drainage systems, lighting, and lane markings. Before ribbon-cutting, the structure is subjected to Florida Department of Transportation inspection and certification. For DOT projects, the process is rigorous; Charley Toppino & Sons has the certifications and track record to see it through.
All bridges eventually need to be replaced, whether because of age, storm damage, increased demand, or new construction in the area. Bridge demolition contractors do more than just tear things down. This work involves assessing the structure, securing environmental permits, planning the demolition sequence, removing debris, and preparing the site for what comes next.
In the Florida Keys, taking down a bridge over open water in an environmentally sensitive area is even more complicated and requires strict compliance with federal and state rules. The process includes managing debris, protecting water quality, and working closely with agencies like NOAA and the Florida DEP. There is no room for shortcuts when working above a protected marine sanctuary.
At Charley Toppino & Sons, we handle demolition as part of our complete range of services. Whether a structure needs to be removed to make way for something new or as part of a larger project, we handle everything from the initial assessment to debris removal and site preparation.
Building in the Florida Keys is unlike working anywhere else. Bridge construction companies here face challenges associated with saltwater corrosion, marine foundations, strict environmental permits, limited road access, and the challenge of working over open water. For contractors without experience in this area, the learning curve is steep.
Charley Toppino & Sons has built the Florida Keys for over 100 years. Our highway bridge construction work spans everything from municipal repairs to large-scale DOT replacement projects. That experience shows up in how we plan, how we problem-solve in the field, and how our work holds up over time in one of the country’s harshest environments.
If you’re planning a project in the Florida Keys, contact us. We know the Keys, and we’re ready to dig in.
Truss bridges are often considered the strongest for the amount of material they use because their triangle-shaped framework distributes weight well. For carrying the heaviest loads over long distances, cable-stayed and suspension are top choices. The best design depends on the span length, load requirements, site conditions, and budget.
The most common highway bridge types are beam, arch, truss, and segmental concrete. Beam bridges are the simplest and are used most often for short distances. Segmental concrete bridges — which are made from precast sections joined together — are popular in Florida, especially in the Keys, because they last a long time and can be built in pieces over water.
The time it takes depends on the project’s size and complexity. Replacing a small city bridge might take a few months from start to finish. Building a large highway bridge can take two to four years, and planning, permits, and engineering often take just as long as the actual building. In the Florida Keys, navigating environmental regulations tends to add a few weeks (or even months) to the schedule.
Heavy highway construction means building big roads and infrastructure, like highways and the systems that support them, such as earthwork and drainage. These projects are larger and more complex than regular commercial construction. They need special equipment, skilled workers, and experience with long, multi-stage projects. Building bridges is one of the toughest parts of heavy highway construction.
