HEAVY TRAFFIC

Timaru Herald, Volume CXXXVII, Issue 19483, 6 May 1933, Page 12

HEAVY TRAFFIC

AN AMERICAN VIEWPOINT. In a recent report the United States Joint Committee of Railroads and Highway Users laid down the following policy: “The apportionment of various types should be based upon use of facilities required, and should be sufficient to pay their fair share of total annual costs.” In the case of trucks, to what extent do they use the highways? How much do they add to road building and maintenance costs, and how is their “fair share” of these costs to be determined and apportioned among the various types of trucks? These and kindred questions were discussed by H. H. Kelly, of the division of highway transport of the United States Bureau of Public Roads at a subsequent meeting of the New York State Motor Truck Association.

At the outset Mr. Kelly declared that, according to traffic surveys, commercial vehicles are found in considerable numbers only on main highways; that they are exceeded nine to one by private passenger cars, and that their use of the roads is “nothing more than marginal.”

“The trucks have not dictated, nor even vitally influenced, the creation of our vast network of main roads,” he said. “That creation is the child of the private passenger vehicles, 23,000,000 of them. Our modern highways are given additional width, and easier grades, and wider curves, in order that the private car owner may have greater safety and comfort in the high-speed traffic of to-day. He has a right to them, for he pays his full share of the bill for them. But the point is that our main roads would have to be just as safe and smooth as they actually are, even if there were not a vehicle in existence heavier than a seven-passenger limousine.” Damage to Roads. Analysing the forces destructive of road surfaces, Mr. Kelly asserted that “the effect of the heavy truck on the highway is no greater than that of the passenger car,” except as regards “punching shear”—the tendency to “punch holes in an inadequately constructed surface” —and impact (greatly diminished by the use, now almost universal, of pneumatic tyres). In order to combat these, gi‘eater strength must be built into the highways, entailing higher cost.

Mr. Kelly held that trucks should not be assigned a special share in the cost of bridges, since these structures are seldom designed for average traffic alone, but are given additional strength to withstand the movement of heavy road-building equipment, army tanks, and mounted artillery, and other “exceptional loads.”

The influence of the truck upon highway and bridge costs “has been exaggerated,” according to Mr. Kelly. He estimates that during the last seven or eight years “aboait 90 per cent, of all trucks built in the United States have been of one and a half ton capacity or less, or not much more than the heaviest passenger car, and only 10 per cent, are heavier than that.”

Trucks as a whole “already pay a lot for the facilities they enjoy,” Mr. Kelly said. “In 1932 the total taxes paid by all motor-vehicles, including license fees, petrol taxes, oil taxes, Federal excise taxes, and other imposts, have been estimated at 1,099,000,000 dollars. Of this amount it is conservatively estimated that trucks paid 25 per cent. That in itself sounds like a substantial contribution to highway costs.”