Overpass

overpass

[′ō·vər‚pas]

(civil engineering)

A grade separation in which traffic at the higher level is raised, and traffic at the lower level moves at approximately its original level.

The upper level at such a grade separation.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Overpass

 

a bridge built at the intersection of two or more main transportation arteries that allows for the free flow of traffic on different levels. Overpasses are commonly constructed where highways and railroads intersect or over city streets that have both heavy vehicular and passenger traffic.

An overpass can be either rectilinear or curvilinear, dependent on the type of intersection or the configuration of the intersecting city streets. Sometimes overpasses are arranged in several tiers and their spans are located one above the other. Most overpasses are either beam or frame structures because it is necessary to keep the spans low and because of the limited space that is available for piers; arch structures are comparatively rare. Currently, most overpasses are built from precast reinforced concrete. They usually consist of two to four spans, each 10–30 m long. Overpasses with more than four or five spans are called viaducts.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.