AMERICAN HIGHWAYS

Evening Star, Issue 19792, 16 February 1928, Page 3

AMERICAN HIGHWAYS

CONCRETE MAIN ROADS AUSTRALIAN’S IMPRESSIONS There is in Wellington at present Mr Clia.les W. Lloyd, a member of the Executive Committee of the National Roads Association of Australia, who lias just returned from a tour of the United States, during which he attended a conference of 1,250 delegates from all parts of America and the world regarding reading problems (says the ‘Post’). Mr Lloyd’s impressions in the cities visited by him were that, whatever was the material for roads used for lighter traffic, which varied considerably according to the nature of the conditions, concrete was becoming universally used for the construction of main highways. In Canada he found that a fair amount of crude oil was being used for surfacing, and stood light traffic very well. Heavy snows in British Columbia and Vancouver prevented him seeing much of the roads there. He motored 1,200 miles to San Francisco, and stayed two days in Seattle, where he found a fair amount of asphalt being used, but most arterial roads being put down in concrete. The Mayor of Portland, Mr George Baker, when asked his opinion of the material to bo used for main roads, said that it gave him concern to think of the amount of money that had been spent in “ black ” road's, meaning bitumen, and that while he was in office, wherever he could manage it, .concrete was going down. Not only had he found the bitumen roads dangerous when wet, on account of their throwing light back from the surface, but they would not stand up to heavy traffic like cement. In San Francisco Mr Lloyd found a difference from all other American cities. Tlkerc they were going in for enormous lengths of brick roads, on a concrete base, and these were proving satisfactory. In the highways in the mountains, however, cement stood out predominantly. In Los Angeles he found more bitumen and asphalt being used than in any other American city, but ho was given to understand by the city engineer that this was only in his limits. These extended over a space of fifty by thirty miles. Outside that concrete was being largely used. The' soil was largely clay, and the trouble of expansion and contraction was being met by the use of concrete slabs, TOft by 12ft, Sin tick, for heavy traffic, with an ex [landing joint of fibre and asphalt. A nAnckland linn was supplying quite a largo proportion of the fibre used. A novel sort of road was found in New Orleans, where a plentiful supply of oyster shells was being used. This was put down under pressure, and there was sufficient lime in the shell to bind the surface satisfactorily. In Washington he found cement the most popular material, bitumen not being much in favor. In only one place did he find bitumen used as a covering for cement, at'Buffalo. In New York a fair amount of bitumen was being used, nbnt the majority of the roads were in concrete paving, and the city engineer there informed him that in future concrete was to be used in place of bitumen.

The balance of opinion at the roads conference at Cleveland was that all main highways should be put down in cement blocks, providing that the necessary expansion and contraction could be provided for. The general practice in laying the blocks seemed to be to cover the road with a strong hardwood coat, and allow the traffic itself to solidify the surface preparatory to paving. This would appear to he expensive, but the wooden coating could be used again and again. Only a few months were required to bring the road down to the state at which it would give no further under traffic. Very little crown was now being put on the concrete roads, but on the long highways these were banked steeply at nil bends, so as to allow a speed of lortyfivo miles an hour round the corners. Her found the stage motor routes very comfortable. From Vancouver to San Francisco the stage cut some seven hours off the train times for the distance. The buses kept up ,a speed of over Jifty-niiio miles an hour. They were very comfortably upholstered, and the scats, with head rests, as commodious as a barber’s chair, could be lowered by pulling a lever into a reclining position, in which sleep is easily possible, while at the halts the accommodation and meals were excellent.