This English translation of the successful French edition presents the conception and design of steel and steel-concrete composite bridges, from simple beam bridges to cable supported structures. The book focuses primarily on road bridges, emphasizing the basis of their conception and the fundamentals that must be considered to assure structural safety and serviceability, as well as highlighting the necessary design checks. The principles are extended in later chapters to railway bridges as well as bridges for pedestrians and cyclists. Particular attention is paid to consideration of the dynamic performance.