ROAD:

1a. abbr. Rd. An open, generally public way for the passage of vehicles, people, and animals. b. The surface of a road; a roadbed. 2. A course or path: the road to riches. 3. A railroad. 4. Nautical A roadstead. Often used in the plural.

Etymology: Middle English rode, rade, a riding, road, from Old English r d. See reidh- in Appendix I.

Appendix I: Indo-European Roots: reidh- To ride. Derivatives include raid, road, and array.
I. Basic form *reidh-. 1a. raid, road, from Old English r d, a riding, road, from Germanic *raid-.

Ancient roadbuilders:

Mesopotamians - in 3500 BC.
Chinese - by the 11th century BC and by the 2nd century BC were responsible for the famous Silk Road, evocative and romantic (to me at least – I know ‘fings ain’t wot they useta be’, but still).
Incas - built a network of roads through the Andes, including galleries cut through solid rock.
Babylonians - had a system of roads radiating from Babylon.
Egyptians - built highways for the transport of materials used in building the pyramids etc.
Romans - the Appian Way was begun about 312 BC, the Flaminian Way about 220 BC.

The Roman Empire eventually had a road system of about 80,000 km and their work can still be seen. Roman roads are noted for running in a straight line, but even where the road follows a ridge or the valley of a river the curves are not smooth. Instead, the road was laid out in short straight lengths following the terrain, aligned from one high point to another with the road following each alignment right up to the angle. Most roads were defined by curb stones on each side.

Major Roman roads were laid upon an embankment, called an agger, to form a sub-base. The agger could either be just an earth bank or, using layers of stone or other locally available material, raised up to 5 feet high and 50 feet wide with a layer of stones at the bottom to provide drainage. This bottom layer of the agger is the statumen.

The lower part of the road proper, the rudus, was of gravel and sand sometimes mixed with clay, and compacted in several successive layers. This was really what we would call the road base, laid on top of the agger.

The upper layers of the road were paved with gravel, flint or other small, broken stones. After the second century B.C. stone slabs were sometimes used for paving; from that time roads had to be paved in towns, but sand or pebbles sufficed on country sections. The total depth of a road, from surface to the top of the agger, could be 1.5 meters with the surface steeply sloped to each side from the centre.

Theme will continue tomorrow.