Ever since we started driving, at least in the United States, we know that brake lamps burn steady and turn signals flash. Every car has operated the same way for many decades. These aftermarket electronic modules that flash the brake lamps are mixing-and-matching modes of lamp operation in an attempt to sell a product in the name of safety.
If you’re directly behind said Camaro (or Jeep or whatever else it is), you’ll be able to see both brake lamps and the CHMSL. When those brake lamps start flashing, what do you do next? A flashing brake lamp means he’s put on his 4-way hazard flashers, right? Well, to confirm that, we’d need to move our eyes to find the CHMSL. With that also on, we would then know that the driver is stopping. The time it takes to move your eyes to that CHMSL and process the operation of the three lamps together is unnecessary. It removes your attention from the road and increases your reaction time. And that’s really the best case scenario.
Worst case, you’re in the lane next to the Camaro, perhaps near his rear bumper, and you see the brake lamps begin to flash in your peripheral vision. What’s he going to do next? Is he slowing down? Is he signaling a lane change? You don’t know; you can’t see his other brake lamp and you can’t see his CHMSL. Ambiguity has no business on the road.
In my opinion, steady-state brake lamps are even more critical in North America, where red turns signals are permitted. In some other parts of the world, you know a red lamp is a brake lamp. But in North America, a red lamp could be a brake lamp...it could be a turn signal…it could be a 4-way flasher. This is why they’re required to be steady-burning…steady-burning means “stop”.