Article: Minnesota: Red Light Camera Removal Improved Safety
New data shows the lack of red light cameras in Minneapolis, Minnesota has had no negative effect on traffic safety. In 2005, the city was able to issue automated traffic tickets for just eight-and-a-half months before being stopped by a series of court rulings finding the program in violation of state law. The Minneapolis Star Tribune reported that since the cameras were turned off, accidents have gone down.
City Department of Public Works accident data comparing equivalent time periods show that one year prior to the installation of cameras, there were 104 accidents. In the time cameras were in use, the number dropped to 69 -- a figure used to show how successful the cameras had been. Except in the year following the cameras' removal, accidents dropped to 61.
Because these figures compare three sets of just eight-and-a-half month's worth of data, their value is limited. Often, red light cameras are installed at a time when accidents are unusually high to take advantage of the statistical phenomenon known as regression to the mean. As the number of accidents returns to a "normal" level, city officials credit the change to their camera program. This example illustrates the regression effect by showing an even greater drop in accidents happened without the cameras in use.
In April last year, state Supreme Court ended all appeals and outlawed the use of red light cameras in the state (view ruling