I for one was very happy to see the introduction of the AR class licence.
Prior to that a class A licence required you to show up for a drivers test with a full-on tractor trailer and I doubt you'd be able to find a truck driver training school that would let you use their truck if you didn't take their course. This meant almost nobody did it.
The result was a 55 year old person with the best part of 40 years driving experience but never drove anything than a sedan nor pulled so much as a 4' x 8' box trailer could go out and buy a diesel dually and a 40' fifth wheel that weighs 14,000 pounds and head out without anyone bothering to check he's qualified to do so. I'm not very comfortable with that.
BTW, the above 'guy' is my neighbour and really did just that.
Ontario is notorious for allowing the most ludicrous things to be registered without asking any questions let alone saying no. Case in point, I looked at a Volvo tractor with a custom totter body on it a few years back, ownership was in it, the truck was registered at 4,500 KG as if it was a pickup. That truck weighed likely close to double that.
Nobody at the MTO thought maybe a tractor weighed a titch over that?
