Dave, I don't disagree with your concerns. But the statistics don't prove them correct.
My Son works for a tow service. The percentage of vehicle wrecks that involve Alcohol/Drugs is so small it's miniscule when compared to other causes. Biggest cause by a WIDE margin is inattentive driving. Cell phones, laptops, newspapers, books, applying makeup, tuning the radio, adjusting the heat/AC, dozing off, excessive speed, any pair of these exceed Alcohohl/Drugs.
They have had three wreckers totaled in the last three years. All three were hit by passing motorists when working a scene with all lights flashing. Twice the vehicle that hit them had both lanes of the Interstate hiway open. One was talking on the phone. One simply said they thought they were going to miss the wrecker. Misjudged that by about 2 feet. Totaled the wrecker and the Super Duty being driven. None of the three involved any altering drugs or alcohol, stoned sober.
Again, not condoning, just clarifying that society has a serious driving problem and the minimal part is alcohol/drug abuse.
Fatality Facts
IIHS only tracks alchohol >.08 in terms of substance abuse. I've known people that can't walk/talk properly well below .08.
Long ago, Transport Canada put together a program testing the driving skills of people impaired on various substances, on a closed course. Some of the most surprising results were with people who'd had just one drink, but were taking an OTC cough/cold/allergy medication. Yep, tells you not to do that on the consumer packaging, but plenty of people pay no attention.
There are lots of alcohol related crashes that don't show up in the official stats, and "other" drug impairments don't seemed to be tracked
at all.
The 3 types of lies - Lies, **** Lies, and Statistics

are one reason I pay attention to what has been going on at street-level....
EMS has it tough - even with all lights going at the side of the road, they still get hit, including by drivers not "on" something.
Police cruiser got folded in half by a dump-truck a few years back. Cruiser was parked on the side of the 401 w. lights ON, middle of Toronto, daylight, good weather. Fortunately, the LEO was not in the cruiser at the time.
The above reality being on my mind meant that the 2 times over the years that I've changed a flat on the side of an expressway meant that while I may never qualify for a NASCAR pit crew, my times on those 2 days were not that far off either :thumbsup: .
Friend of mine owns a heavy-tow company. Was put in hospital by a roadside hit like you describe. Woman driver was a known-heavy drinker that squeezed him between her vehicle and his truck. She took off and disappeared/hid the vehicle for long enough that no DUI charge could be made.
Summer long weekend about 2 years ago, a drunk dump-truck driver hit the Burlington Skyway bridge superstructure
with his raised dump bed, at highway speed. All witnesses agreed, the guy was blotto drunk. Fast forward to the court case - it gets thrown out, as it took the OPP too long to administer the final blood test. Can't imagine why, they only had about a million vehicles to redirect off that bridge

.
There are still significant accidents happening where alcohol is the
primary cause, that don't show up in the official reporting.
But, you get no argument there from me Richard; there is a big problem
in general with people doing everything
but paying attention to their driving when behind the wheel. Those Nissan commercials you describe seriously irritate me too. I'll be surprised if Nissan doesn't get sued for portraying a soft-roader mall crawler blasting past heavy equipment operating in an off-highway scene.
Most of us recognize that the relatively strict (compared to 50 years ago) alcohol related driving laws have had a measurable impact on reducing drunk-driving to the lower levels of today. Few of us would want to rescind our drunk-driving laws.
My main point is that MJ impairment laws
including reliable road-side impairment tests need to in place
before it is actively marketed as a recreational tax-generating drug.
Rgds, D.