Speed limits have a long history that is largely unrelated to ticketing.  The do seem slow today but they made sense only a few years ago, before the magic that is modern rubber tires.  Road noise, fuel efficiency and the prevention of congestion have also been factors.<p>The recent rise in for-profit ticketing has less to do with low speed limits than the steady increase in penalties.  The decriminalization of speeding has also increased the incentives for cops to ticket quickly and often.