JUNE 2021CONSTRUCTIONBUSINESSREVIEW.COM8As long as people have been living in communities, they have been building bridges. Bridges span physical obstacles, connect societies across boundaries, and transform possibilities for people on both sides of those divides. While there are bridges in Greece built in the 13th Century BCE that are still functional, most modern structures have life spans that are slightly more limited since they accommodate considerably heavier traffic. Bridges today are designed for a projected service life that takes into account the local conditions and intensity of use. As those limits are reached, they become less reliable, more costly to maintain, and often become inadequateas their usage demand grows. Communities and municipalities are faced with decisions about how to replace these vital crossings and what to look for in designing for the future. These projects are an ongoing part of infrastructure management and have escalated over the past 10 to 15 years as older structures age out of usefulness or safety standards. Bridge rebuilding offers an opportunity not just to duplicate the old structure, but to utilize advancements in engineering and materials to design bridges with substantially longer service lives that can also address the unique needs of the community they serve.For many years, planners viewed managing automobile traffic as the sole purpose for building a bridge, with little thought given to pedestrians or cyclists who might want to, or may need to share the roadway. As more people choose to ride bikes and walk to stay healthy or as an alternative to driving, they are often using the same roads and bridges that have long been devoted to cars, sometimes leading to dangerous situations. To address this, bridge designers today often include plans for their bridges to accommodate multiple uses. Pensacola Bay Bridge: One example of this is the new Pensacola Bay Bridge in Florida which opened to traffic last fall. The old bridge, constructed in 1960, was nearing the end of its service life. It had only four travel lanes and its daily traffic counts of approximately 55,000 often caused congestion even during off-peak times. Without an auxiliary lane, a single traffic incident or disabled vehicle on the bridge could snarl traffic for hours. When FDOT analyses revealed that replacement would be more cost-effective than attempting BRIDGES BUILT YESTERDAY, TODAY AND FOR TOMORROWBy Brian C. Stieritz, PE, Executive Vice President Southeast, Skanska USA CivilBrian C. StieritzIN MYOPINION
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