Here's some reading for you. Full version of FMVSS 108, current version.
http://www.ecfr.gov/cgi-bin/text-idx?node=se49.6.571_1108
US National Traffic and Motor Vehicle Safety Act of 1966
(This is the Act that eventually established the National Highway Traffic Safety Administration and its authority to write and enforce the Federal Motor Vehicle Safety Standards). Originally located at 15 USC 1394-1410, it has been reorganized and is now located at 49 USC 301. Old to new location conversion of various subsections is
here.
http://www.law.cornell.edu/uscode/text/15/1394
Sections most frequently relevant to discussions on this forum include:
• Old USC 1397(a)(2) = new
49 USC 30122: Prohibits regulated parties to "render inoperative" a mandatory regulated device, system, or design feature; "render inoperative" can mean to remove, disable, damage, destroy, or alter the performance so it is no longer compliant.
• Old USC 1397(a)(1)(A) = new
49 USC 30112(a): Prohibits the manufacture, importation, introduction into interstate commerce, offer, or sale of vehicles or items of regulated vehicle equipment not compliant with all applicable provisions of all applicable Federal Motor Vehicle Safety Standards.
Next you want to find out what the legal definition of " regulated parties ".
If you want to disable the DRL, pull the fuse and simply turn on your headlights when driving during the day, no one will ever question you if they work or not.
DRL's are a safety provision to increase the vehicle conspicuity, and prevent collisions with both pedestrians and people that aren't paying attention.
While I agree with DRL's being mandatory safety equipment, there are times when you want them shut off, for example pulling into a driveway at night, lighting up your neighbors bedroom windows.
