BRIDGE TYPES IN THE CENTRAL ANDES.

Four major bridge types have dominated the central Andean Highlands in the past 400 years: the indigenous hanging bridge of plant materials; the Mediterranean stone arch bridge; the iron-cabled suspension structure with flat roadway; and the steel beam bridge. All three introductions, although technologically superior to the native vine bridge, lagged in their acceptance. Today modern bridges predominate in accessible zones, but archaic bridge types survive in the more remote areas. Bridge morphology and some bridge functions have changed, but the crossing sites have largely remained the same. [ABSTRACT FROM AUTHOR]