ROADING QUESTION.

Thames Star, Volume LVII, Issue 15157, 17 February 1922, Page 8

ROADING QUESTION.

PERMANENT HIGHWAYS.

THEIR REAL VALUE. (By J. F. Holloway in Board and Counci.l) Nothing 1 marks the evolution of a district so clearly as the state and progress of its roading system. This applies not only to the economic, but also to the social or aesthetic end. Good roads not only put value on the acres, but widen the A-ision and improve the social and intellectual status of the inhabitants. One often hears the remark that the average farmer’s vision is limited by his boundary fences. Poor roads unfortunately have this tendency, for the man on the land is apt to remain steeped in the atmosphere of the cowyard and the sheep pen if miles of bad roads separate him from intercourse with his friends and other means of social and intellectual enjoyment. On the other hand, goodroads and motor vehicles annihilate distance and open up fresh vistas —» in fact, make life worth living. An illuminating example of this is to be found in Taranaki, where, at the centres, it is a usual thing for a farmer with his family to just slip in after tea to an entertainment from his farm, say 30 miles distant. Ye Gods! In the old times a day’s journey! From the economic point of view we reach the same conclusion. It is difficult to set in money terms the value of good roads to the farmer as affecting his bodily and mental makeup, but in terms of pounds, shilling and pence, it stands out like a sore thumb. In fact, the advantages are so obvious that it is unnecessary to repeat them. When the old horse waggon, straining over rutty roads, is compared with the motor vehicle carrying four times the load in quarter of the time, further emphasis is needless. The above, no doubt, will be all readily admitted, but the question at once arises: What are these good roads going to cost and how much is necessary to maintain them? . Taking constructional cost first, there are three recognised systems of tar work, namely: (1) Tar sealing; (2) tar grouting; and (3) tar macadam, traffic conditions determining which is the most suitable. The following figures will be found to be approximately correct, though allowance is necessary for abnormal cost of transport of materials. The figures are under those provided by some borough engineers :

TAR SEALING. Cost per square yard. cl. Sweeping old roacl surface .. .22 Spraying and patching old surface. .Si .60 Prepared tar 6.50 Binding 1-30 8.62 Contingencies .. .38 9.00 f

Say, 9d per square yard for one coat. A second coat, should be applied to this road at an additional cost of 6d per square yard, making a total cost of 1/3, or £SOO per mile of 15ft. road. This class of treatment should he applied only to existing roads of substantial construction. It gives good results on roads constructed of broken metal laid on solid foundations. Tar sealing should not be attempted on a weak onpoor-ly-formed road. In other words, no surface treatment will make a poor road good, but will keep a good road from going to pieces, and the wearing surface will be cheaper to maintain, whilst .the cost of renewal is entirely eliminated. ‘•TAR GROUTING.

Where it is desired to construct a new road, the following is the system extensively adopted by New Zealand and American engineers:—Broken metal is spread on a well-rolled sub-grade and thoroughly rolled. A 'heavy prepared tar is then pumped into the metal, blinded with metal chips, and again thoroughly rolled. This surface is then left open to traffic for a few months, after which the surface is again sprayed with prepared tar and blinded. The result is a smooth, resilient-wearing surface, with a tar concrete foundation. The cost of this class of road in ' New Zealand works out as follows, for one mile of 15ft. road: — Tar binder, 11.000 gallons at 1/3 (including deliv-

It is to be remembered that the above figures-are for the construction of an entirely new road capable of carrying the heaviest form of mixed traffic, such as is usually encountered on country roads in the Dominion, or in the ordinary town traffic outside of the heavy traffic of the main centres.

TAR MACADAM. In catering for the heavier city traffic, tar macadam is recommended. This process is an old one, namely, mixing tar and stones in the right proportions, thus presenting a solid mass, which is • well rolled and afterwards given a top-dressing of tar and sand. 'Tar macadam costs approximately 4/- per square yard six inches deep. MAINTENANCE. A comparison of the cost of upkeep of a gravelled road and a road covered with a permanent binder, must include the cost of renewal of the former type of road, and in a good many counties data is available as to costs of individual roads. Many, however, overlook the fact that modern road traffic compels either heavy annual patching or heavy periodic capital outlay for a new metal covering. This is especially the case where heavy and continuous motor traffic obtains. I have in mind an extreme case of a main Taranaki road, carrying huge quantities of dairy produce. In this case a six-inch coating of metal was wiped out in a year. On renewal the council decided to bind the metal. This was some seven years ago. To-day the metal is still intact, and the surface dressing, renewed every two years, costs 15/- per chain per annum. Local authorities generally have recognised that though the first*, cost of a road must necessarily be higher if a permanent binder is used, it is economy in the end, as the cost of upkeep is considerably less.

ery and heating) .. £687 10 0 Stone and chips, 978 yards at 13/635 14 0 Labour at 3d per square yard 109 19 0 Rolling 40 0 0 Interest on plant and sundries 30 0 0 £1,503 3 $ 0