It's not as stupid as you might think. Drivers tend to obey traffic lights even when they can see it's safe -eg a pedestrian crossing after the last person has crossed, or a quiet, well lit crossing when it's clear there are no cars approaching. Even leaving the barriers, the flashing red lights should be replaced with standard red amber green. We associate flashing lights with a warning, not an instruction.
I would be minded to disagree, in that if people are stupid enough to drive around barriers then they aren't going to pay much attention to a different configuration of lights controlling the crossings.