TARRED ROADS.

Taihape Daily Times, 2 October 1919, Page 5

TARRED ROADS.

‘AN ENGINEERS VVARNING.

Mr C. Skitrof, C.E., writing to the New Plymouth Herald pointing out mat -many local bodies in Taranaki are ‘making a great mistake in spending large sums of money on what they ‘consider permanent roads, using as a binder and waterproof covering «wis-till-ed tar, says: There is only one property in tar which is of any value as a bindel~——that is, its oils. They are Vegetable oils, and evaporate rapidly when exposed to atmospheric conditions, leaving Dothiflg but a black, friable material, which can easily be crumbled with the fingers and is of no value for reading purposes. ‘ For the past seven years I have been engaged chiefly in laying down roads in concrete, bitumen, and several tar preparations, including distilled tar, and from actual experience I have no doubt that concrete is the best lasting material for "wheel traflic, but, it has one serious drawback, apart from its heavy. cost, that is, its slippery nature when wet. This makes it unsuitable for country road Where there is still a considerable amount of horse traffic. No horse could keep on its feet at anything but a walking'paee down a grade 1 in 15 laid in concrete when the surface was Wet. Therefore it is only suitable for roads in fairly level country or where there is no horse traflic. .

Bituminous macadam, being always resilcnt, can be laid on steep grades up to 1 in 12 without any -danger of a horse losing its foothold when travelling at a fast pace. It requires very little, if any, more maintenance than concrete. and can be la_id at one-third the cost. Bituminous macadam was laid by the New ‘York City Council (in Park Avenue) 21 years ago, and was reported to be in good condition three years ago, and the maintenance cost had been nu. ‘