It is dangerous enough when a person operates a passenger car or average size vehicle while under the influence of alcohol or drugs but to drive a commercial vehicle while under the influence is quite another. This is especially true for semi truck drivers. Think how small you feel in your car when one is next to you on the road.
When you drink or drive it affects your reflexes making it extremely dangerous since a semi truck takes much longer to come to a stop when braking making it imperative for the driver to have unaffected reflexes. It is sad and upsetting to even think about the consequences of a loaded semi "bumping" into a car much less slamming into a car.
The current federal law makes a truck driver's alcohol BAC level a 0.04 and if a truck driver does he is now considered to be legally impaired. When you think about the size of a commercial vehicle versus an average sized car this is acceptable and warranted and has aided in reducing accidents in recent years.
However, drugs like marijuana or stimulants can also cause impairments and this is a problem since many truck drivers believe that these are helpful in keeping them awake when driving long routes. It is a fact that many truck drivers are forced to drive until they have pushed their own limits in order to keep impossible deadlines or even their job, but that has caused the drivers of commercial vehicles to also turn to drugs like meth which are easily purchased at just about every truck stop along the way. It is not easy to determine who is at fault, the truck driver or the company pushing them, but one this is for sure and that is that the polices are in dire need of reviewing.
Fortunately truck drivers for all companies are subject to random drug tests. It doesn't matter what they happen to be doing, they could be getting ready to head out, and then suddenly have to report to their supervisor's office to submit to a test. This is another example of implied consent, having accepted their Commercial Driver's License they have consented to these tests and have no grounds to refuse. If they do refuse they are subject to termination from the company or at the very least some sort of fine.
This is always a situation that is serious enough that it will have to be looked further into. It is even more serious than a normal DWI, because of the number of lives potentially at stake. Every driver of a passenger car who has to drive next to a semi truck will want some sort of assurance that they are safe and that the truck driver won't be suffering some problems, like flashback to a war he was in, just because he had took some substance to help remain awake.
For the truck driver he needs to keep in mind that there are many innocent lives at risk should he give in to temptations or pressure from deadlines The bottom line is to get the sleep you need, it's partly your responsibility.