airbags -- cheap, saves lives, downside is possible added injury due to deployment but overall benefit is worth it
seatbelts -- very cheap, saves lives.
automated traffic system -- vastly increases costs, reduces traffic congestion, reduces traffic fatalities only if the system is perfect and the mechanical parts never fail. What if you blow a tire? The car behind you might still plow into you, only now instead of at 70 mph it's plowing into you at 150 mph. What if the actual auto-drive system fails? Maybe you swerve into oncoming traffic. This is just hardware failure. What if you get hacked / get a "virus"?
In actuality, I didn't mean to imply the ACLU is a means to stifle innovation, but rather there is a legitimate argument to be made that such a system does discriminate against the lower classes. That IS a battle the ACLU would fight.