The 50 percent increase in gasoline and diesel fuel taxes is being urged by a federal commission to finance highway construction and repair until the government devises another way for motorists to pay for using public roads. The National Commission on Surface Transportation Infrastructure Financing, a 15-member panel created by Congress, is the second group in a year to call for higher fuel taxes. In a report expected in late January, members of the infrastructure financing commission say they will urge Congress to raise the gas tax by 10 cents a gallon and the diesel fuel tax by 12 to 15 cents a gallon. At the same time, the commission will recommend tying the fuel tax rates to inflation. The commission will also recommend that states raise their fuel taxes and make greater use of toll roads and fees for rush-hour driving. A tax increase on this order would be politically treacherous for Democratic leaders in Congress, as it is typically a highly controversial issue. U.S. President-elect Barack Obama has expressed concern about raising gas taxes in the current economic climate. But commission members said the government must find the money somewhere.