Social Security, Medicare, Transportation trusts.
All were set up by Congress, all funded by taxes, all underfunded because Congress fails to act responsibly or tell Americans the truth about the need to keep raising taxes to maintain the obligations it creates.
If a program is established and funded by payroll taxes or in this case gasoline taxes, it should be expected those taxes must be raised to continue to fund the promises made by the programs.
Instead when it comes to raising the taxes many in Congress decide the taxes are unfair so nothing happens and trusts are depleted.
Or, funding must come from general revenue and these programs end up in the morass of politics and competing with all other funding demands and associated wrangling.
So much for dedicated funding.