OCR Text |
Show TYPES CF ROAD MATERIALS j Th:ro Has Ezen Great Change in Highways Suitable for All Traf-fio Traf-fio Conditions. In the last ten years there has been u great change in the type of road suitable for iruJic conditions on main traveled highways, according to engineers engi-neers of t! e bureau of public roads of the United Slates Department of Agri culture. In liilO plain and surface-treated surface-treated macadam were considered among the highest types of paving for country roads and n large percentage of the mileage was of the two types. There was a small mileage of brick nnd concrete and a somewhat greater mileage of bituminous macadam, but the plain and surface-treated macadam ma-cadam were the predominant types oi hard-surfaced roads. How great the change has been is shown by figures recently Issued by the bureau. On fei'eral-nld roads completed between 1010 and 1020 only 2.0 per cent of the total nrea paved was plain and surface-treated macadam. The types that formerly constituted such a small part of the mileage were us follows: Bituminous macadam, !!.l per cent; bituminous concrete. 0.3 per cent; cement ce-ment concrete, 19..1 per cent, and brick, 4.1 er cent. |