He emergency highway energy conservation act was passed in 1974. under this act, states would only get federal highway funding if they set a speed limit of 55 mph on all four-lane highways. why would the federal government deny funding the states instead of just directly setting the speed limit? the federal government wanted to better allocate money by cutting down on highway funding. state legislatures were not likely to reduce the speed limit to 55 mph on their own. states were thought to have the right to regulate their own intrastate highways. studies by the federal government indicated that driving 65 mph was unsafe.