The battleground over traffic enforcement cameras may be shifting.

Nearly half of all states use cameras to track red-light or speeding violations, and some use both. But while the number of communities nationwide that use red-light cameras is gradually falling, the number of speed cameras is slowly rising.

New Jersey legislators recently discontinued the state's red-light camera pilot program after five years. The program was marred by a computer glitch that voided thousands of tickets and a federal lawsuit that resulted in millions of dollars in refunds.

Lawmakers in other states have curtailed or modified their camera programs, though courts recently upheld the use of the cameras in Ohio, California and Illinois. A ruling is pending in Missouri's Supreme Court.