From USPIRG.org

A first of its kind nationwide study finds one in five Americans live where traffic cameras are used. It is also recommendeds safeguards be put in place to protect municipalities and drivers. 

The new research report outlined problems with the growing trend among cities to outsource traffic enforcement to red-light and speed camera vendors.

The report, titled "Caution: Red Light Cameras Ahead; The Risks of Privatizing Traffic Law Enforcement and How to Protect the Public" showed that approximately half of U.S. states enable the use of automated traffic law enforcement. The nationwide policy study found that one in five Americans live in jurisdictions with traffic camera ticketing contracts.

It described which kind of contracts are most problematic for the public: those that create a direct financial incentive to issue more tickets and create penalties that limit the public's ability to lengthen yellow light intervals or other alternative ways to promote traffic safety.

The report recommended stronger guidelines to ensure that automated traffic enforcement programs focus on improving road safety, rather than ticket revenue...

It also recommended camera vendors should:
• Put public safety first in decisions regarding enforcement of traffic laws - this includes evaluating privatized law enforcement camera systems against alternative options without regard to potential revenues.
• Ensure that contract language is free from potential conflicts of interest
• Avoid direct or indirect incentives for vendors that are based on the volume of tickets or fines.
• Retain public control over traffic policy and engineering decisions, including cancelling contracts if the public is dissatisfied.
• Ensure that the process of contracting with vendors is completely open, with ample opportunity for public participation and each ticket listing where to find online data about automated ticketing for each intersection.