0 a long, high bridge, usually held up by many arches, that carries a railway or a road over a valley:
a railway viaduct
1 a high bridge that carries a road or railroad over an area that is difficult to cross, such as a deep valley, very wet land, or the steep side of a hill:
The itinerant specialist and the gradual erasure of local variation were as much the product of the railway age as its viaducts and tunnels.
These hypotheses are much more extreme than those generally accepted for viaducts.
A tall viaduct pier, such as the one we are planning, could thus simply be composed of four corner uprights, built in the form of caissons.
The viaduct's preservation bestows on it a permanence which is curiously at odds with the marginal situation which provided the conditions for its survival after 1964.
That viaduct is in a bleak area of the countryside and has stood there for more than 100 years, battered by winds and storms.
We have tested the central reservation rails on a number of sections of the midland link viaducts.
The main road is very narrow—in some places tankers will have to slow down to two miles an hour—and there are numerous bridges and viaducts.
I had to spend eight hours a day in a railway booking office situated under a viaduct.