My father, only partly jokingly, used to say that one of the issues with car safety is that people who cause accidents don't bare the cost/brunt/result of their bad driving. "If we mounted spikes on the steering wheel", he said "long sharp spikes" so that if you braked suddenly or hit someone, you would get a long sharp spike in your chest, "everyone would drive much more carefully and never drive drunk". Actually, I suspect this might not hold for adolescents who believe they are immortal.
Part of the problem, as Dick Lewontin, the population geneticist used to say, is that people aren't good at integrating. That is, they don't do well with calculating the area under the curve. Thus a narrow spike, like 9/11 changes our government (has dept. of homeland security really done anything to merit the amount of money it sucks up?), our lives, and everything else. I am not saying that the lives lost were not important, or that it wasn't a horrible event. I'm talking about the proportionality of the response. A small, steady, but constant problem, like drunk driving, which isn't dramatic, has a bigger impact over time, but doesn't get the attention. Some would say this echoes our nervous system: we respond better to edges than to gradual changes.
According to the CDC:
In 2015, 10,265 people died in alcohol-impaired driving crashes, accounting for nearly one-third (29%) of all traffic-related deaths in the United States
One bit of information is that drunk driving is only 1/3 of the deaths, so we're talking about >30,000 per year in car deaths. The deaths in 9/11 were a one-time count of 2996 (note: the deaths due to 9/11 may be rising due to pulmonary complications. acknowledged. check. but those deaths are not what the response was about).
It's been 16 years, and in that time (doing the integration) 480,000 people have died in traffic accidents.
Although awareness of drunk driving has increased. Certainly, it more important than it was when I was young. But, despite the level of attention it receives, there is still an issue, and one about which we, as a society, are reluctant to grasp and address. Certainly if we compare the response to 9/11 to that of drunk driving, we come up short.
There are lots of reasons. There are reasons that promote dealing with 9/11 and others that reduce the attention on drunk driving. Politics: those in power tend to drink but not fly planes into buildings. Politics: you look good by advocating a strong stance on terrorism. Heck, let's declare war on a noun.
And drunk driving is only one thing. There are other, largely preventable causes of death, including other substance abuse, faulty infrastructure, being it fire safety or hurricane preparedness. I suspect there is more public money going into hurricane response (if you are white, etc... Do not forget Puerto Rico) than infrastructure in general. But hurricanes are dramatic one off things, as opposed to the slow daily and deadly drip of people killed by drunk drivers. We like the dramatic things, but we just can't integrate under the curve.