The State of Illinois Department of Transportation has started an ambitious new enforcement program for laws against speeding. Beginning in July and in response to several highway worker deaths, speeding in "Work Zones" will bring a $375 fine (first offense) and a $1,000 fine and 90-day suspension (second offense). The law will be enforced by camera vans that will take images of the driver's face and license plate. Pictures and bills will be mailed to your home. The State of Illinois Department of Transportation is through fooling around.
I think there are two reasons they're using cameras and radar rather than conventional police cars. First, it's difficult for a police car to pursue speeders in the single (possibly crowded) lane that is typical of many work zones. And, second, when there's a $1,000 on the table, you don't want even a hint of human fallibility to enter the situation: You want the (ostensible) certainty of a radar-based camera system.
This technique gets interesting when states (or better yet, the federal government, which likely would welcome a chance to audit state enforcement of speeding laws) start using satellite-based detection. Put down two lines a mile apart and have the satellite track how long it takes each car to cross from one to the other. Military-grade satellites can supposedly already read license plates--I'm assuming (based on exhaustive research in which I rolled a 20-sided die until I got a number that looked about right) that civilian-grade technology will catch up in a decade or so. In fact, put down a line every mile along every stretch of highway within the jurisdiction and charge a fine for each line crossed above the limit. You could drive home and find 40 e-mails informing you that on your trip you had racked up 40 individual fines totaling appreciably more than your monthly rent. I like this solution because government can do it unilaterally: It doesn't require any broad technology rollout (such as RFID in every vehicle) and the civil liberties question has already been settled--US courts have ruled that you can have no expectation of privacy when you're in public. Happy trails.