I don't think that lowering the speed limit will help. Speeding is as easy as cheating on your diet, you know you shouldn't, but you do. What MIGHT help more is transforming crosswalks into speed hump crosswalks. If drivers value their cars, it will force them to slow down.
I'm sure that it will generate more speeding tickets. That's the goal, right?
I think maybe it will help slow some drivers down even though when I'm driving home at 25 some drivers behind me are like tail gating and once I turn in my Area they zoom like I was going slow. I Also think in school zones it should be 15mph. For our children's safety..