Here is a start from Illinois DOT website:
http://www.dot.state.il.us/workzone/Q&AsPhotoEnforce.pdf
1. Why use photo speed enforcement?
Photo Speed Enforcement will be used to increase safety on Illinois highways and to
obtain voluntary compliance by motorists to obey posted speed limits. Motorists
represent 85% of the fatalities in work zones. Between 6,000 and 7,000 crashes occur
in work zones. Slower speeds will allow motorists more time to react to changed
conditions.
2. When would photo speed enforcement be in use?
Photo speed enforcement by an automated traffic control system may operate only
during those periods when workers are present in the construction or maintenance zone,
day or night.
3. When workers are behind Temporary Concrete Barrier (TCB) can photo speed
enforcement be used?
Photo enforcement legislation requires workers to be present. While Temporary
Concrete Barriers provide positive protection for workers, they are not impenetrable.
Vehicles have hit and broken through TCB, causing injury to workers. Also, lane width
restrictions may require reduced speed limits to ensure the safety of the motorists. For
these reasons, photo enforcement may be used when workers are present.
4. Will a special sign have to be in place for photo speed enforcement to be used?
Yes. Initially, photo speed enforcement will be limited to interstates and expressways.
Signs indicating that speeds are photo enforced by automated traffic control systems will
be clearly posted in the area where the systems may be in use. In addition, the vans will
have a speed indicator device that will be triggered by separate radar and will
communicate the vehicle's speed to the motorist. This will give the motorist one last
opportunity to slow down before the camera radar is triggered.
5. Do I have an opportunity to slow down before the camera takes my picture?
Yes. If the motorist does not slow down, the camera radar will be triggered. A photo of
the driver, vehicle, and license plate will be taken. The time of day and speed will also
be captured.
6. What if the equipment is not working correctly?
Illinois State Police will man these vans with troopers specially trained in photo radar
enforcement. They will calibrate the equipment prior to each enforcement detail to make
sure everything is working correctly.
Illinois Department of Transportation - FAQ - Photo Enforcement
7. Do I have to appear in court for a violation received with photo speed enforcement?
Yes.
8. What is the ticketing process?
A ticket will be processed by the vendor and will be approved by the on-duty officer.
Tickets will be mailed by certified mail to the registered owner within 14 days. The
violator will receive the ticket and will be required to appear in court.
9. What are the photo speed enforcement fines?
Work zone fines will apply.
