Suspending the federal  gas tax  could bring down prices at the pump. But the move may not provide consumers with meaningful relief, experts say, and it could deplete a key federal fund for highway construction and maintenance. On Monday, President Donald Trump said in Oval Office remarks that he would "reduce" the tax, after saying in an interview with  CBS News  that he wants to pause it "for a period of time." The taxes and other fees on retail gasoline and diesel fuel are 18.4 cents per gallon for gas and 24.4 cents per gallon for diesel, according to the U.S. Energy Information Administration . Reducing or pausing the federal gas tax would require congressional approval, but several Republican lawmakers immediately advanced proposals to do just that on the heels of Trump's remarks. Following Trump's comments, Sen. Josh Hawley, R-Mo., introduced legislation that would suspend the federal gas tax on gasoline and diesel fuel for at least 90 days if enacted.…