PHOENIX — At the first tick of the clock Friday, an array of automated cameras on Arizona freeways aimed at catching speeders were to stop clicking.

There is no glitch. The state, the first to adopt such cameras on its highways in October 2008, has become the first to pull the plug, bowing to the wishes of a vocal band of conservative activists who complained that photo enforcement intruded on privacy and was mainly designed to raise money.

It was a tumultuous, impassioned run here. A man wearing a monkey mask racked up dozens of tickets, fighting them in court, to protest the system. Vandals at different times attacked the cameras with Silly String and a pickax.

More seriously, the operator of a van carrying a mobile speed camera was shot to death on the side of a freeway in April 2009. The suspect is being prosecuted on first-degree murder charges and the family of the victim has announced a lawsuit against the state Department of Public Safety.

Gov. Jan Brewer, a Republican seeking election to a full term, never embraced the program, begun under her predecessor, Janet Napolitano, a Democrat whose revenue projections from the tickets fell short largely for a simple reason: Violators tended to ignore them.

The cameras, which included 76 units either mounted near the shoulder or operated from vans, were adept at snapping speeders as they whizzed past sensors, but getting offenders to pay after the tickets were mailed to them was another matter.

Less than a third of the 1.2 million tickets issued were paid, and the state collected $78 million, far below the projected $120 million annual revenue.

Some of those tickets, typically $181 apiece, no doubt were lost in the mail; others no doubt were not paid as violators tested a legal theory that they needed to be served in person. Process servers who were supposed to follow up could hardly keep up with the load.

Brewer made no secret of her disdain for the system operated by Redflex Traffic Systems, which will turn off the cameras the moment its contract expires.

"She opposed this program because it was designed primarily as a state revenue-generation tool," Brewer’s spokesman, Paul Senseman, said this week. "She also is uncomfortable with the intrusive nature of the system. She is willing to allow the voters the opportunity to decide the future fate of the system, and anticipates there will be continued discussion and debate of the proposal in the Arizona Legislature."

Some of the loudest critics were conservatives, who organized protest groups and prodded legislators to impose restrictions on their use, arguing that the cameras amounted to, as one put it, the "government spying on its citizens."

"It is unconstitutional," said Shawn Dow, founder of Arizona Citizens Against Photo Radar, who also questioned the safety benefit and the propriety of having Redflex, whose parent company is based in Australia, involved in issuing tickets to Americans.

The Department of Public Safety had reported a 19 percent drop in fatal collisions in the first nine months the cameras were in use, but after Brewer took office and named a new director of the department, no further data were released.

The Insurance Institute for Highway Safety has backed photo radar systems as a public safety improvement and says their use is increasing, mostly to catch drivers running red lights. Red light cameras are now used in 475 communities, including New York City, and speed cameras in 57 jurisdictions, according to the institute.

A spokeswoman for Redflex, whose camera systems in 14 cities in Arizona are unaffected by the state’s withdrawal, predicted speeding would spike on the freeways.

"Though few government agencies have opted to deactivate road-safety camera systems, we have learned from those that speeds will spike to dangerous levels," said Shoba Vaitheeswaran, a spokeswoman for Redflex.