If someone is asking about the driving age here in the US, there is no consistent driving age that applies to all states because this is not established by federal law. Rather states establish the law for their own jurisdiction, and well if a person drives out of state, the state they're driving in respects the law of the person's home state. (AKA a person who is 16 and lives in a state that has a driving age of 16 drives into a state where the driving age is 17...this is permissable, but a person who is the legal resident of the state where it is 17 can't drive there...)
When I was living in New Jersey, which is where I was born and grew up until 16 the driving age was 17. When my parents retired and moved to Maine, the driving age was 16 (with a learners permit at 15.5). I'm not sure what the driving age is in NM here, as I didn't move here until I was 25...and then it didn't matter for me anymore.
Speed limits can also very as defined by state also...where for instance here in New Mexico the speed limit on the interstates outside the city is 75 mph. Back East it was much more commonly 65 mph, and some states never did increase it above 55 mph. Some states like Massechusettes had it 55 on their interstates except for the Mass Turnpkike which was 65 mph, at least for a while there. In Montana which I've vacationed before, there was only a night time and truck driver speed limit of 65 mph, but for everyone else none was defined; just "what is reasonable and proper"...
The wearing of seat belts is also mandatory in many states, at least the states I've lived in... Again it's left up to state law and the state legislators here...
Oh and to the advertising, yes we have seen advertising like this before; aka ciggerette commercials. And for awhile there the tobacco companies even sold on the idea that tobacco smoke could help people lose weight. Again the targetting of young teenage girls who are weight conscious and want to look like the super-models who in some cases are on the verge of anerexia...