The typical spans between columns of the South Bay Expressway's Otay River Bridge measure 300 feet, or about the length of a football field. Photo: South Bay Expressway

As the last segment of a new toll bridge was put in place in late March, California transportation officials looked forward to the end of a major traffic headache.

The South Bay Expressway's Otay River Bridge is part of a new, 10-mile express toll road, built for $635 million, that opens this summer. The ¾-mile, four-lane bridge is expected to free up local traffic snarls in the San Diego area by connecting residents to employment centers on either side of the structure.

Made of post-tensioned concrete, the bridge is designed to withstand the force of a large earthquake. Using pre-cast segments enabled the bridge to be erected relatively quickly, minimizing the project's impact on the surrounding environment.

Under an agreement with California DOT (Caltrans), the South Bay Expressway Partnership Ltd.—owned by Australia-based Macquarie Infrastructure Group, a company that has taken over toll roads in Illinois, Indiana, Virginia, and other states—will operate and maintain the expressway and the bridge. The agreement requires the partnership to invest $20 million in local environmental mitigation efforts such as wildlife habitats and awareness programs.

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