THE ROADS PROBLEM.

Dominion, Volume 7, Issue 2214, 29 July 1914, Page 10

THE ROADS PROBLEM.

AN ENGINEER'S" VIEW. SOME PRACTICAL SUGGESTIONS This .article is written by Mr. Sydney A. R.> Mair, engineer to the Rangitikei County Council and vicepresident of the New Zealand 1 Society of Civil Engineers, who. has made a number of interesting experiments in road construction. A practical road engineer often wonders if motor''.traffic nad not suddenly sprung upon- the community and brougnt tnem face to face with this burning question, how long the people would nave submitted to, our antiquated road building methods.' b'or years we road engineers fuddled on in our own ways, without uniformity in our work, or any thought but to appease the ratep?;ers of the present. Wo made and mended day by day in the same old way,'while the public grumbled. and paid. But in a lew short years all is changed; With the advent of motorcars road builders soon realised that instead of a blessing cars were a curse to road maintenance, and although tho public were, at first hard to come to this belief, it is now. generally conceded, even by motorists themselves, that car traffic is detrimental' to road' surfaces in direct proportion to' weight and speed. The net result now is that almost every organisation, representative of the people has its little bit to say and methods to suggest to help remedy the trouble. This is directly reflected in Parliament, where a genuine desire is now do or find some way out of the difficulty that" will not unduly penalise the. public. For the time being—based on our old methods and means at our; disposal—we road builderj have to confess we are, to put it mildly, "cornered." All the world over, new methods and substances are being used with varying success, and almost daily the champion of some of these springs into the 'flashlight ■ before the public. However, very little real data is given, so that local bodies have each to apply and test under local conditibns in an : , experimental way before definite conclusions can be drawn. Some Financial Difficulties. The very valuable reports. of ' county, engineers throughout the Wellington province, recently published in U'he Dominion, show that local bodies themselves have grasped the situation, and arc genuinely grappling with' the best means within, tneir reach. A pleasing feature-is the now-almost general adoption of an up-to-date road-making plant, which is tne first, essential for, good roads. While on this it may be well to emphasise that in tho past the serious initial cost of a complete road-building plant, quarries, etc.,- has not been contemplated by our legislators, and no power exists ; for rural districts to raiso a loan for the purpose! The acquisition of quarries with a' full equipment of graders, ploughs, scoops, crushers, rollers, concrete-mixers, water-carts, tar-sprayers, etc., runs into thousands of pounds, and'to purchase these out of general rate is a serious handicap for, an average county. The power to. borrow under.special order for.tho-purpose would case the way for many local au-' thorities to make a move with a forward road-building policy. '- To build ii good country road, the grades, foundation, and 'draining arothe first essentials. If these aro slummed, in the■ first instance, the future life and effectiveness are greatly minimised, and to alter or amend means.a heavy expenditure. Quality of metal or gravel comes nest in importance, and iu future this must have tho greatest wo in selection. Even at far greater expense it will be found moro economical to have good metal than substitute stuff-niore easily obtained. For this reason, especial facilities should bo given over our railways to enable sidings and light lines to be laid to suitable quarries for general distribution of good metal. Also the carriage of metal for road purposes should have every consideration at cheap rates, instead- of being, 'as at present, treated as secondary traffic. . With good, clean, metal, and cheap cement there is no doubt concrete offers the solution in the near future for motor, roads, but the above conditions must'obtam in their entirety hqforo this hope can be attained. / Where Motor Traffic Tolls,' In Roman ages no expense or labour was spared in road building, and sometimes- a great thickness of rock matrix was laid,, but now, apart from a solid foundation, the surface, or. point of contact with wheels, is tho point of weakness. Old methods of traction and weight operated in grinding and compressing the surface and producing tension in the extreme bottom portion of metal' coat which, as it became disintegrated, had the greasy foundation squeezed up through to the surface. These: again became mixed, and lively, with rain and traffic, eventually cutting 'into ruts. Present day traffic has almost the opposite effect, as beyond the general "creep" due to excessive speed, the most of the damage is to the'extreme surface, which in every well-built road is of its finest materials. These, aro sucked up and blown or kicked off by the tires in dry weather,' and in each depression, so made water lodges. This intensifies the trouble, and any blinding not blown away is quickly swished away :when '(wet. Having determined the actual manner and cause of the wear, the next thing is to combat it' cheaply and.- efficiently. Experience shows so far that- good metal laid on a good foundation is a comparatively thin coat consistent . with the weight it has to carry, and bound with liner metal substances, then -thoroughly rolled in water bond, makes the best resistant to the' creep or traffic waves. To overcome the surface wear is our next trouble, and our country experience shows that a surface or seal of sonie. impervious resilient substance is required.• Crude tar and tar compounds, mineral oils, and hosts of substances are being tried with greater or lessor degree of success. The writer has inspected many of these, which are giving satisfaction, and has obtained excellent results, combining efficiency -and cheapness, from Mr.- Basham's roster, now a commercial product, manufactuied in Wanganui, and soltar, being made in Auckland, ,tlie former being somewhat the cheaper. ■. Cost of a Water-bound Road. To sum up the position at the present stage, a well-made water-bound macadam road, with a tar compound seal, is within the practical realms of every rural local -body; .and will be found the most efficient to stand the mixed motor and produce traffic obtaining on general country roads. The costof an average standard country road as outlined above, excluding formation, would, with good, clean, crusher-broken metal at 7s. 6d. per cubic yard, cost approximately per chain as follows:— £ s. d. 20 cubic yards metal, spread and roiled in water-bond, with 10-ton roller, at Ss. Cd. per cubic yard S ,10 0 Tar compound seal, ivtili sand gravel blinding, i-incli thick, 88 cubic yards, at 9d. ...:..;. " 3 6 () Total cost per chain, , complete 11 1G 0 Now that the public have come to recognise that motors do rjause execssivo :damage to roads,, and that- bad roads mean 'discomfort and danger in travel-

ling, and increased cost of upkeep of I cars, and that with a small financial assistance good 'roads are ' within tho ! ra'ngo of most county authorities, tho proposed l motor_ tax is universally welcomed. There is a great diversity of opinion as to lioiv this should be raised and haw it should be. dispersed to ensure a direct benefit to the roads, and not merely to relieve districts of the responsibility of rates.!'.. At present n uniform tax on horsepower is proposed, but n«.'-the damago done by a car is in direct ratio to —(a) its weight,'"(b) lio'rse-power, and (c) distance travelled, it seems hardly equitable that a man who only uses his car once a week should pay as much as tho man on the road all day and every day, and who must do damage in proportion. If a system of graduated taxation could be devised by which'each car could have registered its weight and liorse-power, and bo fitted with a registered speedometer, under the seal of'the' registration office,' it would be far more equitably and just'. However, such a suggestion bristles with difficulties, but I think all these could be overcome, as has been dqne with gas and 'water meters, cash registers, and other tell-tale devices. -Another very good suggestion is to lay the tax on tires, as these again, although varying in quality, wear generally in proportion to use made of the car, and he who wears most tires does most damage to roads, as weight, speed, and distance travelled are directly reflected in wear of tires. Exception may be made to.this method as tires are being manufactured in the Dominion, but these, too, could be similarly taxed by being held in bond by manufacturers till tax is paid, and tires, stamped by a Crown officer. The Question of Control. By far the most difficult aspect is the equitable distribution of the tax when collected. Presumably if a- "main roads board." or "works board" h set up by Parliament, the car tax will bo at its disposal to .' allocate evenly on the ■ road • lines . directly affected by car. traffic. If the . tax is applied to main lines only no difficulty should bo found in a proper officer checking the average daily traffic, and the board could apportion the fund accordingly. By this' means local bodies wouldbe partly relieved of cost of maintenance of their main'roads and have more funds available for by-toads subject to only intermittent car traffic. A strong feeling seems to permeate portions of the Dominion that all main roads should be Solely maintained by tho Government. This, however, is extremely dobateable for .various'reasons, "tindou'btedly the public purse should subsidise all arterial rbads.-whieh are so essential to the marketing of the country's products. It is also plainly Parliament's 'duty to see that all local bodies are. of sufficient size and fvnancially able to keep up an efficient roadbuilding staff and plant. These ;would then be in direct touch with 1 the taxpayers arid-producers, and better equipped in every' way to efficiently build and "maintain the roads than is possible by the Public "Works engineers located in centres often many miles from tho works in hand and officers possibly overburdened with, the many constructive and other duties which usually fall to their lot. In many instances it would mean keeping- duplicate plant and stall in a district tho cost' of which necessarily decreases r tho-net funds.available for actual work) These conditions have long obtained much to the detriment of the development of thobackblocks in;many parts of the Dominion. Another disability in Government control is that the Public Works appropriations arc brought down late in the season, and still further delayed in being authorised till a whole summer season 'is lost and, or worse still, the work is often undertaken during the winter months, greatly adding to the cost and limiting the extent... With a local body directly the appropriations are made on the Estimates the work can be put in hand out of ordinary local revenue and ,I'proupptl when' the grant is made available; However, a very reasonable restriction is that the expenditure should; as at present, be approved and-finally certified by a Government engineer, to safeguard the general taxpayer. Where Metal Is Scarcer ■ Ha,ving dealt with road building whore metal is available wo now come to districts' where Nature has passed us over. These usually are tho most rugged though perhaps fertile, localities away back from the~ivaterfront or main lines of communication. Here wo havo a full field to tax the -abilities of our road builders. For some years burned papa or clay have beei\ tried, the success varying according to the quality of materials and knowledge and experience of the burners. Many thousand yards havo been burned by the writer, with a result quite up to expectations, and it can be confidently claimed.that a wellburned papa road, put down under nor r mal conditions compares favourably with the average metalled back-block road in both cost and effioiency. Road builders have much in front of them yet regarding calcining papa and clay for metal, and the' near future'will see a marked rate.of progress. ■ Present methods are crude,,and a large proportion'of the heat' generated is lost, but the day of mechanical or electrical calcining-is coming to. cheer the back-blocker. It is also -clearly established by experience that the quality of burnt-papa or clay is greatly dependent on the compositionof tho raw material, and of the three great tcrtiery bods commonly known - as papa the "lower", or. "Agillaceaus" is the . best for > the purpose, . while "Arenaceous" or middle •is poor, the "Calcareous!' or upper is quite useless.The common failure to get good results in many districts can generally be traced_ to the selection of the wrong materials by the men engaged on the work. v • In pajssing I may venture to say that, with the recent incorporation of the New Zealand Society of Civil' Engineers a now era for all roading and engineering problems as appertaining to local bodies has beon opened up. The days of individual plodding in the dark have gone, .and all road building problems of such vital importance to the public will, l at the annual, meetings of the society, be dealt with and debated by the best of our engineering talent, and- it is confidently anticipated that the standard of our work will thereby, be very materially raised. One of the society's paramount duties will be, by collecting data through delegates, and publications of.all kindred societies and associations, to keep the engineers of the Dominion in direct touch with the procress now being made throughout" the world in this vital subject.