Why would a national speed limit be effective during the oil crisis in 1973? people were speeding to the gas stations. more accidents meant more energy used. it would conserve energy by limiting fuel consumption. there was no speed limit until this time.

a woodchuck would chuck 12.5 wood : 3

congress also has implied powers, which derive from the necessary and proper clause of the constitution and permit congress "to make all laws which shall be necessary and proper for carrying into execution the foregoing powers, and all other powers vested by this constitution in the government of the united states.