The Courtney Campbell Trail bridge has four strategically placed overlooks from which bikers and walkers can pause to take in the views of the bay. Courtesy of Florida DOT
As part of its efforts to reduce pedestrian and bicyclist deaths, the Florida Department of Transportation has constructed a 45 ft high bridge to carry a new trail across Old Tampa Bay.
October 1, 2013—According to the Florida Department of Transportation (FDOT), the Sunshine State has nearly twice as many pedestrian deaths as the national average, and if the Tampa Bay area alone were a state, it would rank 16th for pedestrian fatalities. Furthermore, Florida has been repeatedly cited as the deadliest state in the nation for bicyclists. As a result, the FDOT has adopted an initiative aimed at reducing pedestrian and bicyclist fatalities by 20 percent by 2015. As part of that plan, the department recently completed a new bridge that carries a new pedestrian and bicycle trail across the expanse of water in the northwestern part of Tampa Bay that is referred to as Old Tampa Bay to connect existing and future trails in two counties. The project also included the construction of a 3 mi segment of the new trail.
The new bridge for the Courtney Campbell Trail parallels the Courtney Campbell Causeway, which carries Route 60 between Florida’s Hillsborough and Pinellas counties. The new crossing gives pedestrians and bicyclists an alternative to the busy four-lane causeway and also provides the first nonvehicular crossing of Old Tampa Bay since the nearby Friendship Trail Bridge closed in 2008 for safety reasons. The new bridge and trail are part of the FDOT’s goal to enhance pedestrian and bicycle safety through improved law enforcement, education, and engineering, says Kristen Carson, a public information officer for the FDOT’s District 7. The department plans to extend the trail in 2015 to connect it with existing trails in Pinellas County. “We’re having a real problem with pedestrian and bicyclist deaths,” Carson says. “So we are very proud of this project because it’s a trail just for those travelers.”
A new 3 mi long pedestrian and bicycle trail has been constructed
along the Courtney Campbell Causeway in Hillsborough County,
Florida. A new bridge carries the trail across the bay to Pinellas
County, from which it will be extended at a later date. Courtesy
of Florida DOT
The FDOT received federal support to help fund the $15-million bridge and new, 3 mi long segment of the Courtney Campbell Trail in Hillsborough County. The project was awarded as a design/build contract. The Tampa office of the American Bridge Company, which is headquartered in Coraopolis, Pennsylvania, was the design/build contractor, and the Tampa office of Ayres Associates, an engineering and architecture firm headquartered in Eau Claire, Wisconsin, was the engineer of record on the project. In accordance with the contract, the project had to be completed within 450 days, a time frame established by the design/build contractor in view of the urgent need for the new pedestrian and bicycle route, says Gordana Jovanovic, the design project manager for the FDOT.
Construction of the new trail and the 3,250 ft long bridge began in April 2012. Located no more than 100 ft south of the existing causeway, the new, T-beam bridge was designed to have the same vertical and horizontal clearances as the existing vehicular bridge. As a result, the bridge has a maximum vertical clearance of 45 ft over the bay’s navigational channel. “This is the highest dedicated trail bridge in Florida,” Jovanovic says. “It mimics the existing bridge, so there is no confusion for the boaters.” Furthermore, the fender system that lines the navigational channel beneath the causeway was lengthened to extend under the new bridge as well. That system comprises prestressed pilings and a composite plastic railing with an attached catwalk.
While the bridge height is the same as that of the causeway, the deck is 16 ft wide to match the width of the new approach trail segment. The bridge is wider at four strategically placed observation points, where people can pause to take in the beauty of the bay, Jovanovic says. Temporary framing that extended from the piers made it possible to construct those points 45 ft above the water. “There are a total of four overlooks, two on each side of the bridge,” Jovanovic explains. “It is gorgeous standing there and looking at the bay.”
The new Florida T-beam bridge was designed to have the same
vertical and horizontal clearances as the existing vehicular bridge,
giving it a maximum vertical clearance of 45 ft over the bay’s
navigational channel. Courtesy of Florida DOT
Among the most formidable challenges of the project were designing and constructing the foundation. The bridge has 29 reinforced-concrete hammerhead piers and 30 spans founded on prestressed-concrete piles. Because of varying geotechnical conditions across the bay, driving the piles was by no means a uniform process. Indeed, a unique geotechnical analysis was required for each foundation, Jovanovic says. On the basis of those analyses, some of the foundations had to be redesigned, the work carried out while the driving jig and templates were in place to prevent construction delays, she says. Furthermore, the precast foundation seals were designed as the piles were driven to accommodate construction tolerances. “There was a lot of finesse during the design that required coordination between structural engineers, geotechnical engineers, the contractor, and ultimately FDOT as the reviewing and approving agency,” Jovanovic says. “That was very challenging at the time.”
Other significant challenges of the project included working amid swift ocean currents and controlling turbidity within the sands of the bay to protect the marine life and sea grasses. Steel sheet piles and heavy turbidity curtains were installed around the work areas to calm the currents and reduce the amount of sand that would be disturbed by the construction activity, Jovanovic says. Many agencies, including the U.S. Army Corps of Engineers and the Florida Department of Environmental Protection, were involved in the project to ensure that appropriate measures were implemented to safeguard the marine environment.
Despite the many challenges of working under the unpredictable conditions of Old Tampa Bay, construction of the new bridge and the trail segment was completed in August, several months ahead of the contract deadline. The bridge opened in early September, and the trail has already become a well-traveled route for pedestrians and bicyclists, Jovanovic says. “This project is a vital link for trail users,” she says. “It allows bicyclists and pedestrians to avoid the heavy traffic along the causeway and provides connections to other trails in Pinellas and Hillsborough counties.”