FOR HEAVY TRAFFIC

Evening Post, Volume CVIII, Issue 129, 27 November 1929, Page 9

FOR HEAVY TRAFFIC

NEW, KOAD SURFACES!

WORK DONE LAST YEAR

Eeference to the satisfactory manneij in which the Main Highways Board is progressing with the paving of sections of highway carrying heavy traffic is made in the board's annual report.

When the proposal for the impositioa of the petrol-tax was first placed before Parliament an announcement was inada indicating how the proceeds of the tax were to be used. In particular, a* substantial proportion of the tax was to ba devoted to the payment of higher subsidies towards the cost of paving schemes where the traffic was such' that a higher and more costly type of surface was necessary. Following upon this announcement, schemes were prepared around all the more important centres of population. The details of these schemes were decided upon after collaboration with the local authoritiesand automobile associations. IMPETUS IN SOUTH ISLAND. The development of this phase or the board's work, the .board states, has given a great impetus to expenditure in. the South Isalnd, where- a number of important schemes have been . commenced. The changed attitude in the" South Island has also been largely brought about by the use of the powers given to the board to advariee "money to local authorities under the Main Highways Amendment Acts of 1926 and 1928 in circumstances where it considers this advisable. "One unavoidable result of.. the speeding-up of operations in the South1 Island," says the report, "will of necessity be the retardation to some ex« tent of works in the North 'Island where the local authorities for the past five years have received a heavy proportion, of the . board's construction:, funds. The disinclination of the authorities in the South Island to; proceed with schemes of" construction ia the past has not, of course, affected the distribution of the revenue - fund, details of which are submitted elsewhere in this report. ■.'■■-"..: . ■- CONSTRUCTION DUBmG YEAR. "The class of work : being, carried out under the paving schemes ranges from bituminous surface; treatment of macadam and gravel: roads to.the: construction of Portland-cement: concrete pavements. No less than'l9B miles of dustless roads were constructed during the year, made up as follqws:--jTar "and bituminous , surface ■ treatment,- '122 miles; bituminous . macadam".:(penetration), '51 miles; bituminous concrete,----14 miles; Portland cement"concrete, -11 miles. When it is pointed 'out that the total rural mileage of dustless roads in New Zealand at the 31st March, 1928, was about 639, it will be seen that in .one year the operations tinder the Main Highways Act have increased that mileage by about .30 per cent. While this accomplishment : is' most gratifying, it is nevertheless necessary; to realise the very small proportion which these figures bear to the total length of roads under the control of the Main Highways Board—namely, 10,403 miles. At the present late: :of. progress_ it would take twelve.years to provide dustless surfaces' on only a quarter of the length of the highway* system, and by that time a substantial length of the cheaper surfaces now being laid.down would have reached or would be nearing the end of. its, Useful life. If a more lasting material, such as concrete or bituminous ."concrete, were adopted universally as a surfacing material on the highway system it would take between 30 and 40. years before one'-quatrer of the" present highway system could be surfaced, and long before the expiry'of this perjod^a substantial mileage of the .work' /.^rould have reached the end of its,useful life as a surfacing material." » CONTRACT WORK. Most of the paving work: during the past year has been carried out'by contract, this being in accordance with the board's general policy since it commenced operations. ..In; a-number of cases alternative tenders, have been called for Portland cement : concrete and for bituminous concrete, and, generally speaking prices have .been'very satisfactory. In Hawkes'Bayl ." and Canterbury, in particulari ■ good- tenders have been. received for Portland cement; concrete" construction, .the figures Tanging ..' from -•-• £5800:;: per mile to £6800 per-mite for an: 18ft concrete-road 9in-6in-9in-section^ with, in some cases, 3ffr bituminous shoulders. These prices are" considerably below prices for similar work/in -th^e Auckland district, where aggregate: is':mote costly. •• ■■ ■ ;;, : •;-=-;., ■

Another type of paving for which a number of contracts" have-been':let is single-course ■ bituminous", concrete. Pavements of this class, and of a'thickness of 2Jin, are being'laid, -where aggregate is reasonably cheap, at a cost of between 5s and 6s per . square yard, or about £3000 per mile, for an 18ft pavement. . ; -