Renewed efforts to legalize the use of traffic light cameras in Connecticut, announced recently in New Haven, raise the same troubling questions about due process, fairness and privacy that previous, unsuccessful campaigns failed to answer. The American Civil Liberties Union of Connecticut will continue to oppose any measure to permit them in the state.

Traffic light cameras severely compromise the constitutional right of due process. The owner of a vehicle is ticketed because the camera photographs the license plate but can't identify the actual driver. And the driver never has a chance to confront an accuser.

"The presumption that the owner of the car and the driver are one and the same is often wrong, yet the owner is always ticketed," said Andrew Schneider, executive director of the ACLU of Connecticut. "Also, when a police officer pulls someone over, the driver has a chance to explain any extenuating circumstance and the officer may recognize that, for instance, the driver was moving out of the way of an emergency vehicle."

Concern about these fundamental constitutional conflicts has caused 15 states, including Maine and New Hampshire, to ban traffic light cameras. The city of Los Angeles abandoned its seven-year-old traffic light camera system in July 2011 because the courts could not enforce fines against people whose identities were in question. In Houston and Albuquerque, voters opted in referendums to scrap existing camera systems.

Voters and public officials have found, however, that their decisions about traffic light cameras may ignite legal battles with the private companies that operate them. The companies may collect as much as half of the revenue generated by fines, a strong incentive to enforce contracts and maximize ticketing. The contracts may also restrict the government in the way it sets public policy and enforces traffic laws.

In Houston, the voters' call to turn the cameras off brought a $25 million breach of contract claim from the contractor, American Traffic Solutions. In Tennessee, American Traffic Solutions has sued the city of Knoxville and Redflex Traffic Systems has sued the town of Farragut over a state law that bans tickets for illegal turns when based only on evidence from automated cameras. The companies say their contracts require the municipalities to fine the drivers and share the revenue.

"Private companies simply should not be setting public policy or collecting revenue from law enforcement," Schneider said. "Public safety and justice - not profit - should be the goals of traffic enforcement, and it should be in the hands of people accountable to the public."

The expansion of surveillance to traffic light cameras also opens the door for misuse of the data collected. Not only will the government have access to the data, but so will the private contractor who collected it., "This data could be used to track individual cars and violate the owners' privacy," Schneider said

Supporters of traffic light cameras argue that none of these considerations outweighs the safety benefits, but claims of increased safety have been unconvincing. Research funded by the private companies and governments that profit from traffic-light camera revenues have cited reductions in certain kinds of collisions, but many independent studies and reviews have reached opposite conclusions.

For example, a 2008 study by researchers from the University of South Florida in the Florida Public Health Review concluded that traffic-light cameras increase the risk of crashes and injuries. In both Denver and Los Angeles, city auditors reported that the supposed safety benefits of established traffic-light cameras in those cities had not been proven.