The Amtrak derailment in North Philadelphia just highlights the real safety concerns that too many critics out there have about America's rail infrastructure. According to the Department of Transportation, Pennsylvania's bridges are ranked worst in the country in terms of structural integrity - with 23% of them considered deficient. Many of those bridges have rails that carry oil trains. US railways now transport nearly ten percent of America's crude oil output, or around 800,000 barrels per day; that's a 1700 percent increase in just the last four years. And all that extra traffic just increases the likelihood of rail accidents.