I'd like to see some actual numbers on that, because I flat-out don't believe that claim.
If speeding tickets were reduced to 0, do you think more or less or exactly the same amount of people would speed?
You're making several bad assumptions that nullify whatever point you were trying to make: that the punishment is the only thing that controls how often someone violates the law (other factors include culture and internal morals); that the punishment is "effectively 0"; and that the converse of "much more likely" is not "no difference".