CONGRESS used the threat of withdrawal of highway funds to get all 50 states to lower the speed limit to 55. From my quote of the amicus brief: Defendants have

CONGRESS used the threat of withdrawal of highway funds to get all 50 states to lower the speed limit to 55. From my quote of the amicus brief: Defendants have thus violated the APA by promulgating a policy based on factors WHICH CONGRESSS DID NOT INTEND IT TO CONSIDER ( the all-caps is for emphasis because I can't see italics well anymore and HN doesn't have bold; I'm not yelling :) )