Well, I can say with all honesty that I do not believe what the DOT/USGOV/INsurance tells me because I do not live in the US. I live in Canada where DRLs have been mandatory for years and where I have had first hand experience comparing cars that had them and cars that did not. What I have found is that a DRLs alert a driver to oncoming traffic more than vehicles that do not. When you see the lights, you actually are on a higher level of alert. These days, drivers need all the alert that can receive being distracted by cell phones, sat nav systems and anything else a car company can squeeze onto the dash and centre console.