This is a bad law. I would like to see the number of fatalities, number of trucks involved in accidents and number of truck accidents (especially rear end crashes) that occurred before and after ON and QC implemented their speed limiter laws.
I would bet they are all higher since speed limiters took over the speed of the truck. There is more truck accidents, more trucks per accident and more fatalities due to the inevitable tailgating that this causes
http://www.thetruckersreport.com/ata-wants-mandatory-speed-limiters-set-at-65mph/