I know lots of other prescription drugs do not allow for driving or the operation of heavy equipment - I would feel better if I can be reassured that there are not "high" drivers out there.
That's not really possible as things stand. Whether drugs are legalized, or not.
Impaired driving, reckless driving of any kind are already illegal.
If there was some kind of a 15-30 second test a driver had to take before being able to pull the car, that would confirm his reflex, and mental capacity to drive, that would be great, but other issues would come up.
I have seen that the criminal elements will not go away...
When cigarettes went up in price the enterprising criminal
elements smuggled cheap cigarettes into Canada and made
a killing underselling the main stream legal sellers that were
locked into their selling prices.
The criminal element was created by that increase in price.
If pot is legalized it will not deter the criminal element they
will just adjust their strategy... the prior "illegal pot" will still
be available but for less since the criminal element will not
be paying the exorbitant taxes that will inevitably be applied
to the "legal" pot just like they do for cigarettes and alcohol.
Of course criminal elements will always exist, and always adapt.
Consider that what we have now in the US is effectively a prohibition.
Looking at the history of the Alcohol prohibition in the 1920's, this was also the time when what we think of as the Mafia was effectively created, to meet the enormous demand.
Are there still illegal activities where booze is concerned? Absolutely.
There are tons of fake spirits out there, and what is effectively moonshine.
Still, I feel a whole lot better purchasing my vodka, cognac, and beer in a licensed liquor store, versus some alleyway.
It's really a question of economics. If large companies were to get in on this, the efficiency brought to the process would drive out all but the most determined criminals. There just wouldn't be enough of a profit in it for them.
Edit:
http://www.cnn.com/2012/12/13/world/europe/spain-cocaine-breast-implant/index.html?hpt=hp_t3
Chances are if the idiots who did this, waited for the woman to heal a little longer, and coached her better, the drugs would now be in spain. To produce revenue for the scum to further hurt people and profit.