More car travel does not mean more deaths unless one cannot change the rate of death per mile. Since many locales have much lower per mile death rates, we demonstrably have the ability to improve there. A casual observation of the way local motorists drive will further show that our motorists don't obey any laws, so we have great potential to save lives. 

Want to stop drunk driving? Zero-tolerance traffic law enforcement does it quite nicely. At first, this will simply lead to citations of sober but scofflaw motorists. As they learn and clean up their acts, the drunks will begin to stand out like sore thumbs. It's all a signal to noise issue, as well as the fact that we are currently choosing to not enforce our traffic laws so no one is even looking for the signal.