I work with computers <a href=" http://www.sfbbm.se/how-long-does-40-mg-propranolol-last.pdf#shall ">propranolol bula infarmed</a> The problem for lawmakers is that the existing per-gallon gas tax has hit a point of diminishing returns, as Americans drive less and vehicles become more fuel efficient. The federal Highway Trust Fund, which gives money to states for highway construction and repairs, for example, has needed a congressional bailout four times since 2009, in part the result of no federal gas tax increase in the past 20 years.