Speed cameras in the U.S. and Europe

Unmanned "speed cameras" that enforce local speed limits have become a common roadside feature across the United States, but few places have embraced the devices with the zeal of Iowa.

Across the state, cities big and small have installed the cameras to deter speeding and generate revenue from tickets. The cameras now produce more than 200,000 tickets and $13 million in fines annually, or more than $4 per Iowa resident. (AP)