Show ROAD BUILDING experience VALUABLE the more one studies the subject of road building the more important becomes the matter of impact the blow hit by the wheel official tests of impact of truck wheels on pavement have shown th that it with solid rubber tires this impact is in certain cases seven times the load on one rear wheel encountering an obstruction one inch high while running I 1 16 G miles an hour recognizing the destructive force of a solid tire the oregon motor law taxes a solid tire nearly double the amount of license charged pneumatic tired vehicles it is important that the tire be resilient in order to offset the destructive effects of impact it naturally follows that good effects would be increased on both tires and road surface it if a resilient or shock absorbing pavement was more extensively used this is a very live question in every western state where hundreds of millions of dollars are going into road construction will the roads outlive the bond issues at a minimum maintenance cost or will they disintegrate as have so many miles of rigid surface construction in california with resulting loss to taxpayers through rebuilding the roads under maintenance charges long before the ten year bond period expired california now faces the necessity of surfacing hundreds of miles of roads oads with a bituminous surface to save the concrete base from total de St ruction truc tion the sixth biennial report of the california state highway commission says but regardless of 0 the over laden trucks it t seems apparent that the concrete base should in all cases have the bituminous tops applied as soon ns it may be done the original idea of the commission that bare concrete is not a fit material to receive the impact of heavily loaded vehicles still appears to be sound even the thin bituminous carpet is a great aid in distributing the impact let the taxpayers of western states think |