viaduct

noun

1. A bridge with several spans that carries rail or road traffic over a valley or other obstacles.

   “[…] St. Bede's at this period of its history was perhaps the poorest and most miserable parish in the East End of London. Close-packed, crushed by the buttressed height of the railway viaduct, rendered airless by huge walls of factories, it at once banished lively interest from a stranger's mind and left only a dull oppression of the spirit.”

   “The L.C.C. [London County Council] considers viaducts in London objectionable and a hindrance to town planning and would like to abolish all the Southern Railway lines on viaducts in South London. [Nothing much happened, they still exist.]”