Speed cameras on freeways across Arizona went dark just before midnight last night, ending the state's controversial experiment with photo enforcement.

The short-lived program expired after the state Department of Public Safety decided against renewing its contract with camera vendor Redflex Traffic Systems. Gov. Jan Brewer signaled in January that she planned to bring the cameras down.

From the beginning, photo cameras had been heavily criticized as a government money-making scheme that did not enhance public safety.

The program even incited vandalism of cameras and the fatal shooting of a Redflex technician last year.

Supporters point to studies suggesting photo enforcement reduces crashes and saves lives. And with the cameras gone, Redflex is warning that speeding will spike to dangerous levels.

"This should be a wake-up call to everyone in the community to be even more careful and watch for a large increase in aggressive, dangerous driving," said Shoba Vaitheeswaran, a spokeswoman for Redflex, which has its U.S. headquarters in Phoenix.

Meanwhile, critics are cheering the move as a victory for personal liberties.

Former state Rep. Sam Crump, a Republican who resigned to run for Congress, said the cameras are an abuse of technology in the hands of government and could lead to more intrusive practices.

"I can see the Obama administration putting a chip in every car and saying, 'We'll issue a ticket,' " if you break the law, he said.

Cities with their own speed-camera programs, including Phoenix, Mesa, Scottsdale and Chandler, are not affected by DPS' decision.

Efforts to outlaw photo enforcement statewide through a ballot initiative have not gotten enough voter signatures or have died in the Arizona Legislature.

Redflex has until mid-November to remove its 78 fixed and mobile cameras from Arizona freeways. The company said it will leave the fixed cameras in place through Labor Day to gather data on speeding trends after the program's end.

Crews were to begin removing signs for the cameras around midnight Thursday. The warning signs will be replaced by messages from the Arizona Department of Transportation reminding people to drive safely.

Since the cameras first popped up in September 2008, they have snapped more than 2.7 million times. Of those, only about 16 percent resulted in paid citations, generating $78 million for a fund controlled by the Legislature.

Then-Gov. Janet Napolitano, who shepherded the program before resigning to join the Obama administration last year, famously estimated the cameras would generate $90 million in their first year.

DPS officials have been ambiguous about whether they hope to revive the program sometime in the future.

Two days before a top commander sent a letter to Redflex indicating the agency would let the contract expire, he sent legislators an e-mail lobbying them to support a bill giving DPS full control over the program. That bill passed.

The agency won't answer questions about its lobbying for the bill. But a future governor could bring the cameras back.

Recently appointed DPS Director Robert Halliday has said he scrapped photo enforcement because he was uncomfortable with the perception that DPS was more interested in revenue than safety.

One of Halliday's top priorities as director has been to increase the number of Highway Patrol officers, believing that troopers in marked cars, not cameras, will make Arizona's roadways safer.

However, there is no planned increase in patrol efforts to coincide with the end of photo enforcement, said Robert Bailey, a DPS spokesman. Officers will be "patrolling just like they did the day before," he said.