&gt; perfect enforcement leads to wiping out tickets as a source of revenue, because people start actually obeying the law.<p>Exactly.<p>And this is why most red-light cameras got dismantled.  They were about revenue.  Once everybody knew that the cameras were there, revenue went to zero.<p>I have <i>NO</i> problem with red-light cameras at actually dangerous intersections.  The goal is to get people to obey the law, after all.