[nostromo]

I'm not sure speed bumps scale -- you probably couldn't put one on every residential block. They also have drawbacks, such as slowing down emergency vehicles.

I think there are much more elegant solutions for traffic calming. Like this: http://i.imgur.com/Jn78gQY.jpg

[marak830]

Im not sure about there, but in Australia our emergency service vehicles are a width where they can drive over speed bumps without actually touching (ambulances at least), my brother built them for a while :-)