He's not really changing a whole lot by doing this. As previously stated most airlines do tell you when you fly on a regional.

This seems more like a political move on his part than anything based on the common good.

I imagine he's thinking that if he makes it look like he's an advocate for the average traveler he can parade himself in front of everyone telling them how he saved them from the 'dangerous regionals'

Plus this sounds like something that would actually get passed pretty easily. I doubt there'd be much opposition to this. People are afraid and this helps the senate look like they're doing something about the problem, even if it changes absolutely nothing.