How about slower traffic, less accidents, safer streets?I've argued something similar - that seat belt usage can encourage more aggressive driving habits.
In a never ending quest to make our streets safer and more predictable, we may have actually made them more dangerous and so mind numbingly easy to drive that we enable bad behaviors ... while driving.
Let me reiterate .. the design of our streets may be partially to blame for drivers text messaging.
It's an interesting "what if," but the evidence is anecdotal.