I would consider drug overdoses dramatically different than car accidents. To the point, "dumb things" where you put deadly chemical in jar (fire extinguisher) is not the same as purposely injecting yourself or accidentally losing control of your vehicle.
For what it's worth, while drug fatalities are increasing (arguably there was an intentional act to start drugs, granted addition is less so):
https://en.wikipedia.org/wiki/United_States_drug_overdose_de...
Vehicle fatalities are actually going down per year (and have been, on average, since the inception of the car)
https://en.wikipedia.org/wiki/Motor_vehicle_fatality_rate_in...
> But that aside, a lot of the gains in life expectancy have to do with very basic things - like flush toilets, along with generally improved standards of living.
I agree with you there, lots of minor things like vitamins, clean water, improved environmental controls, etc add up dramatically