There have been no studies to show the modulating headlights are efffectvie.
They have been out for a long time, 30+ years. Just seems funny that no one could ever show they are helpful.
It would sure help sales.
The Feds (DOT) formally approved them for use in 1985. Now there are only three problems: 1) not all States have modified their laws to include the headlight modulator as being acceptable (which is, by itself, against the Federal Statutes), 2) not all the LEO's in states where they are approved know it and 3) no one is making any noise about it. They're too busy worrying about not being able to show off their shaved heads while riding.
This the adoption of these items was slowed down initially because everyone who got one also got a ticket for it. Not only that but remember, if you didn't look bad and dangerous in those days then you just weren't fittin' the image. Safety of any kind just didn't fit the bill. Lookin' like a 1%-er did.
I got a ticket last year for using my headlight modulator even though I'd been using it for over one year at the time. Why? Because the county LEO went strictly by the book, which doesn't address the modulator issue, just the issue of "flashing lights"; which by the way headlight modulators are not by technical definition. However, they are accepted by the MD MVA Attorney General, the State Trooper Safety division (who indicated action is in process to formally change the law), and the MD MVA as a whole. If you read the MD MVA's Motorcycle Operators Manual, pg. 19, it recommends using a headlight modulator. All the research that came up with that info also got me out of paying the ticket. ThumbUp
Studies are good for some things. But I don't need to wait for a study to tell me if I lay down in the middle of the street crosswise during rush hour traffic that I'll get run over. As far as I'm concerned, anything short of a fire in my gas tank that gets me noticed by people who are otherwise occupied by their own personal interests when driving is OK by me. I noticed the difference the first day I used the modulator and I see its value almost every time I'm out riding.
PS. The fact that after 30 years that they are being sold by more than one company should tell you that they must be getting bought by someone.