thats the problem whith people using decades old studies to prove something. yes, back when the cars did get better milage at 55 but that was due to the gearing of the trannies and diffs back then. today they are geared for the higher speeds.
55 sounds good in theory but does anyone know what it actually costs to change all the signs again? figure a minimum of 50 dollars per sign (rough estimate at 35$ pe sign and a very low install cost added also). this was one of the reasons it took so long to get rid of the 55 in the first place the cost to the state and fed to change over. were not talking a few thousand dollars, if i remember correctly the cost was way over 50 million.
once again this is your tax dollars.
if a study was done using todays cars the outlook for savings would be considerably less than they state.
my car at 55 is below the rpm it likes to run at. 65-75 is where it gets its best milage.