https://en.m.wikipedia.org/wiki/Daytime_running_lamp says the study was in 2008....

		bluGill on Oct 25, 2023 \| parent \| context \| favorite \| on: California suspends Cruise's autonomous vehicle de... https://en.m.wikipedia.org/wiki/Daytime_running_lamp says the study was in 2008. I can't find the study itself, but you might have better luck.