CONCRETE ROAD COSTS.

New Zealand Herald, Volume LXII, Issue 19040, 10 June 1925, Page 11

CONCRETE ROAD COSTS.

NEW ZEALAND AND ENGLAND. INTERESTING ; COMPARISON. -DIFFERENCE IN THE METHOD. The " finest road in England " has. just been : completed and opened at an average cost of £125,000 a mile. This is tlie Great West Road, running for a distance of eight miles from The entiro cost was £1,150,000, bub this included the purchase and removal of a number of houses. As the road was surfaced in concrete the. amount involved in the undertaking is of interest in Auckland, where many miles of concrete roads have already been la id; and a further 7£ miles are to be constructed-out of the loan of £710,000 sanctioned by the ratepayers last December..' ,J. ..The Great West Road has a width of 120 ft. and took four and a-half years of intensive and scientific work to make, and it.is-claimed that it is proof against the necessity for repairs, even under the heaviest traffic, for 50 years. Its construction involved the,laying of a foundation of 12in. of broken pieces of concrete, brick and stone. Above that was laid 9in. ■of reinforced concrete, and the whole covered with 2in. of compressed natural rock asphalt. The latest information indicates ;that the average cost worked out at; £7O a yard, but this obviously refers to a running yard, so that the cost would work out in the vicinity of £1 15s a square yard. • . -• The System in Auckland. The Auckland City Council has gone in more extensively for the use of concrete as a paving medium than any other municipality in. New Zealand, and the engineers'have evolved a'system whereby the utmost'efficiency it attained. The method employed is to excavate the width of road to-be laid and to prepare the bottom with a layer of old metal or scoria. The concrete'is then spread in a monolithic slab over the sub-grade to a depth of 6£in. or;7in.' '

The cost works out at between 14s and 18s a square yard, exclusive of the cost of excavation. Most of the concrete paving work in the city includes alterations to,the kerbs to conform to the new levels arid the construction of avails along the edges of the'tram tracks to prevent undermining the concrete when work is being done on the tram lines.' Including this work and the cost of excavation the paving costs approximately £1 a square yard. The construction of an 18ft. strip of concrete along the Great - North Road fro'm-the city boundary at Oakley Creek to Lincoln Road, Henderson, is being carried out by the Gity Council on behalf of the local bodies-along the route. This piece of paving will be about miles in length, and tho cost has been estimated ati £71,770, which works out at approximately. 18s, a square yard. has gone. in for bituminous paveriierits;';particularly. on ".the Hutt Road where'a'pavement in this material laid to ; a thickness of sin. '• cost 9s 8d a square yard. ' /■ ■ , , , Boads in United States. -Much-has been written about the bad roads of New Zealand, but a statement made' by . Mr.' A. Tyndall, engineer to the Main Highways Board, in a report framed after ,an-extensive tour abroad, hardly coincides with the popular view. He says: " New. Zealand's problems are very similar to those being faced in the more thinlypopulated -portions of the United States. Although many millions of pounds have been ' spent on road construction in the United: States in | recent years, it should be realised that tho country claims only 374,000 miles' of ' good roads,' out of a total mileage rof about 2.800,000., The ' good 'roads ' comprise, all the surfaced mileage, . including at least 170,000 miles gravelled., -•* - would appear, therefore, that, New Zealand,; with - 23,000 ' miles surfaced out of a total of 59,000 miles, is well to the fore among ; the newer countries as regards the-proportion of surface mileage (40 per -cent, in New Zealand as against 13.4- per. cent, in the .United States.)."