built for the passage of highway vehicles and pedestrians. Highway bridges are designed for heavy rolling loads of up to 0.8 meganewtons (80,000 tons of force), crowds of people, and other forces. The width of the driving part depends on the expected intensity and speed of the traffic and on the shape and span (usually 7–21 m) of the bridge; the sidewalks are at least 1 m wide.
Highway bridges are made of steel, reinforced concrete, or wood. Girders are most often used in building steel highway bridges. Highway bridges of prefabricated and prestressed reinforced concrete are now built on a large scale. The preferred design of a highway bridge is with the driving in the upper part (deck bridge); this creates better traffic conditions for automobiles and makes the bridge easier to maintain. One of the world’s largest reinforced-concrete bridges with solid girder construction is the highway across the Volga, 2.8 km long and with 166–meter spans, connecting the cities of Saratov and Engel’s (1965). Wooden highway bridges are built mainly on local roads.
REFERENCESGibshman, E. E. Mosty i sooruzheniia na dorogakh. Moscow, 1961.
Spravochnik inzhenera-dorozhnika, vol. 6. Moscow, 1964.
N. N. BOGDANOV