The 55MPH speed limit was introduced in the early-1970s to help reduce oil usage - both domestic and foreign-produced. This limit was removed in the 1990s, even though oil usage has not declined...
Especially as higher speeds require more sustained use of oil, we would save a lot of oil if the law were reinstated, especially as the amount of time saved in driving 65 or 70MPH is only a couple of minutes. Is the extra amount of gas and oil consumed really worth it for the environment, wallets, or anything else?