Sitting here at Discount Tire

[clublights]

As this NHTSA study shows ( from 1998) the effectiveness of the Third Brake light had fallen from 36%( during testing) to 4% by 1995.

The Long-Term Effectiveness of Center High Mounted Stop Lamps ...

The study does not speculate why ( not that I saw during a quick read at least) but here my opinion .. when it was uncommon it stuck out and people noticed once it became commonplace it lost it's effectiveness because it became "normal"

DRL if mandatory will become common place and all the advantages they give will be lost . just like the 3rd brake light. this will of course have the largest effect on motorcyclist since the whole reason they have the headlight on anytime they are running is to increase safety by making them stick out. once they are just a light in a sea of lights.. blam no more safety advantage.

[SAnd]

...DRL if mandatory will become common place and all the advantages they give will be lost . just like the 3rd brake light. this will of course have the largest effect on motorcyclist since the whole reason they have the headlight on anytime they are running is to increase safety by making them stick out. once they are just a light in a sea of lights.. blam no more safety advantage.

There is another safety aspect to running with lights on in daytime. Having your lights on make a vehicle flat out easier to see. It isn't that you "stick out" of the crowd, it's that in some driving conditions you disappear into the background. With lights on your car sticks out of the background, not out of the other cars. I don't think the safety aspect of running with lights on will decrease over time.

[ChadAmberg]

As this NHTSA study shows ( from 1998) the effectiveness of the Third Brake light had fallen from 36%( during testing) to 4% by 1995.

The Long-Term Effectiveness of Center High Mounted Stop Lamps ...

The study does not speculate why ( not that I saw during a quick read at least) but here my opinion .. when it was uncommon it stuck out and people noticed once it became commonplace it lost it's effectiveness because it became "normal"

DRL if mandatory will become common place and all the advantages they give will be lost . just like the 3rd brake light. this will of course have the largest effect on motorcyclist since the whole reason they have the headlight on anytime they are running is to increase safety by making them stick out. once they are just a light in a sea of lights.. blam no more safety advantage.

Look at all the cars where the third brake light are automatically on flashers now. I admit to noticing them while not ever "noticing" normal 3rd brake lights consciously anymore.