principally U.S. highways are now c...

principally U.S. highways are now carrying more and heavier - barters than they were designed to bear. In 1992 combination traffics drove 240 percent more miles across U roads than in 1960 and the total tonnage carried at trucks in 1993 had increased by the agency of nearly 300 percent above 1950 on a levels

One of today's completely weighted 18-wheel semi-trailer trucks has an impact comparable to that of 10000 cars. And, more of the nation's domestic tonnage is moving via the highways: 45 percent in 1993 versus barely 26 percent in 1950. This dramatic increase in heavy traffic flows in faster road breakdown at greater expense to taxpayers.

Moreover, the design standards still used to build and repair highways date from the 1950 and '60 suitable to changes in pavement materials, trade weights, tire pressures, suspension connected views and axle configurations, these standards ne updating.

Now, road researchers