Bridges and tunnels have changed the landscape of transportation and are high-interest topics for young people. They are also excellent examples of the lasting improvement that science, technology, engineering, and math can make in people's lives. Aligned with the NextGen Science Standards, this volume examines the work of early engineers and mathematicians in devising successful bridges and tunnels, as well as the advancements in building materials used over time and the creative challenges experts face today. It will ground young readers in history while introducing up-and-coming innovations.