When first used, the word
causeway appeared in a form such as "causey way", making clear its derivation from the earlier form "causey". This word seems to have come from the same source by two different routes. It derives ultimately, from the Latin for heel, , and most likely comes from the trampling technique to consolidate
earthworks. Originally, the construction of a causeway used earth that had been trodden upon to compact and harden it as much as possible, one layer at a time, often by slaves or flocks of
sheep. Today, this work is done by machines. The same technique would have been used for road embankments, raised river banks, sea banks and
fortification earthworks. The second derivation route is simply the hard, trodden surface of a path. The name by this route came to be applied to any firmly surfaced road. It is now little-used except in dialect and in the names of roads which were originally notable for their solidly made surface. The 1911 Encyclopædia Britannica states: "causey, a mound or dam, which is derived, through the Norman-French (cf. modern ), from the late Latin , a road stamped firm with the feet (, to tread)." The word is comparable in both meanings with the
French '''', from a form of which it reached
English by way of
Norman French. The French adjective carries the meaning of having been given a hardened surface and is used to mean either paved or shod. As a noun is used on the one hand for a metalled carriageway, and on the other for an embankment with or without a road. Other languages have a noun with similar dual meaning. In
Welsh, it is . The Welsh is relevant here, as it also has a verb , meaning to trample. The trampling and ramming technique for consolidating earthworks was used in fortifications and there is a comparable, outmoded form of wall construction technique, used in such work and known as pisé, a word derived not from trampling but from ramming or tamping. The Welsh word translates directly to the English word 'causeway'; it is possible that, with Welsh being a lineal linguistic descendant of the original native British tongues, the English word derives from the Welsh. A transport corridor that is carried instead on a series of arches, perhaps approaching a bridge, is a
viaduct; a short stretch of viaduct is called an
overpass. The distinction between the terms
causeway and
viaduct becomes blurred when flood-relief
culverts are incorporated, though generally a causeway refers to a roadway supported mostly by earth or stone, while a bridge supports a roadway between piers (which may be embedded in embankments). Some low causeways across shore waters become inaccessible when covered at high
tide. ==History==