The day after I posted my blog on the Minnesota bridge collapse on I-35, Chattanooga Times Free Press ran an article on page A8, col 2, that shows the wear and tear on the bridges and highways by the increased truck tonnage. The article was actually written a few days prior to my post and makes it clear that "in just a decade, from 1995 to 2005, the weight load on urban highways increased by half." Bridge loads are increasing at the same time that weather and fatigue weakens the bridges and reduces resistance. Since 1980 the number of tractor trailer miles has more than doubled and risen to 145 billion miles a year. See the full article at: