All child safety seats are secured in the back seat, unless the car (e.g., Honda S2000) doesn't have one. The government standard is for the child to be safely restrained in a 30 MPH frontal crash. If you have doubts as to the efficacy of the laws, here is an article from the National Highway Transportation Safety Administration:
http://www.nhtsa.gov/portal/nhtsa_static_file_downloader.jsp?file=/staticfiles/DOT/NHTSA/Communication%20&%20Consumer%20Information/Traffic%20Tech%20Publications/Associated%20Files/tt331.pdf
Here is some additional information on air bags and children. Children under 12, and even some small adults, are advised to ride in the back seat because of the dangers.
http://www.nhtsa.gov/portal/site/nhtsa/template.MAXIMIZE/menuitem.9f8c7d6359e0e9bbbf30811060008a0c/?javax.portlet.tpst=4670b93a0b088a006bc1d6b760008a0c_ws_MX&javax.portlet.prp_4670b93a0b088a006bc1d6b760008a0c_viewID=detail_view&itemID=61d95a6b35cdff00VgnVCM1000002c567798RCRD&overrideViewName=FAQGroup
I'm not aware of any statistics relating babies and toddlers in the back seat with any increased incidence of accidents. Anything that's distracting to the driver can increase the likelihood of an accident, including cell phone use, fumbling with the radio, putting on makeup, eating... the list goes on and on. I can say that, as a parent, I'm more careful when my daughter is in the car. I stick to the speed limit, keep an interval, stop at the line, and all the other stuff you're supposed to do. I also get far more annoyed with rude and impatient drivers than I ever did before we had her. She stays in the back seat. My eyes stay on the road. I should add that I don't put her in the car any more often than I have to. If other parents are like me, than we probably have fewer accidents, not more.