ROADS, artificial pathways formed through a country for the accommoda tion of travelers and the carriage of commodities. Though the Romans set an example as road-builders, some of their public highways being yet service able, the roads throughout most of Eu rope were in a wretched condition till toward the end of the 18th century. France was in advance of other countries in road making; in England a decided improvement of the highways only began in the 19th century. When diversities of level are necessary, road engineers fix the degree of inclination at the lowest possible point. Telford estimated the maximum inclination of a road to be 1 in 24, but, except in extreme cases, it ;s considered better that it should not ex ceed 1 in 50. The angle of repose, or maximum slope on which a carri•.ge will stand, has been estimated at 1 in 40. A properly constructed road, besides a foundation, consists of two layers, an upper and an under. After a good faun dation is obtained the laying of a base, the best material being concrete of grav el and lime, gives durability to the road. On this base the actual roadway is laid with a slight inclination from the center to the sides for the purpose of drainage.
Before the time of Macadam it was cus tomary to use broken stones of different sizes to form the roadway, the conse quence being that in course of time the smaller stones sank, making the road rough and dangerous. Macadam early in the 19th century (see MACADAM) in troduced the principle of using stones of uniform size from top to bottom. The general superintendence of roadways is usually exercised by the government of a country, but it intrusts the execution of its enactments to local authorities. Highways are public roads which every citizen has a right to use. They are constituted by prescription, by act of leg islature, or by dedication to the public use. What is known as the rule of the road is that in passing other horsemen or carriages, whether going in the same or the opposite direction, the rider or driver must pass on the right hand of the other rider or driver. Automobiles and bicycles are subject to the same re strictions and are entitled to the same privileges as ordinary vehicles.