5/31/2005
Red Light Camera Studies RoundupA collection of red light camera studies over the last decade shows red light cameras have serious side-effects. Updated 7/18
Over the past decade, a number of studies have examined the use of red light cameras. The most relevant studies examined the devices in light of changes in traffic and engineering conditions made at intersections during the study period and pulled actual police reports to examine the particular causes of each collision. The following studies are the most comprehensive available:
- A 2017 Case Western Reserve University study of red light cameras in Houston, Texas found:
"When the camera program ends, we estimate a statistically significant decrease in non-angle accidents of 18 percent in the Houston sample and 28 percent in the Houston-Dallas sample.... Estimates from the Houston sample suggest that the camera program may have increased injuries."
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Full copy, 1.3mb pdf - A 2008 University of South Florida report found:
"Comprehensive studies conclude cameras actually increase crashes and injuries, providing a safety argument not to install them.... public policy should avoid conflicts of interest that enhance revenues for government and private interests at the risk of public safety."
Read a summary Full copy, 80k pdf
Study author responds to criticisms - A 2007 Virginia Department of Transportation study found:
"The cameras were associated with an increase in total crashes... The aggregate EB results suggested that this increase was 29%... The cameras were associated with an increase in the frequency of injury crashes... The aggregate EB results suggested an 18% increase, although the point estimates for individual jurisdictions were substantially higher (59%, 79%, or 89% increases) or lower (6% increase or a 5% decrease)."
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Study author responds to criticisms - A 2006 Winnipeg, Canada city audit found:
"The graph shows an increase of 58% in the number of traffic collisions from 2003 to 2004.... Contrary to long-term expectations, the chart shows an increase in claims at each level of damage with the largest percentage increase appearing at the highest dollar value."
Read a summary Full copy, 541k pdf - A 2005 Virginia DOT study found:
"The cameras are correlated with an increase in total crashes of 8% to 17%."
Read a summary Full copy, 1.7mb pdf - In 2005, The Washington Post found:
"The analysis shows that the number of crashes at locations with cameras more than doubled, from 365 collisions in 1998 to 755 last year. Injury and fatal crashes climbed 81 percent, from 144 such wrecks to 262. Broadside crashes, also known as right-angle or T-bone collisions, rose 30 percent, from 81 to 106 during that time frame."
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Full article on the Post website - A 2004 North Carolina A&T University study found:
"Our findings are more pessimistic, finding no change in angle accidents and large increases in rear-end crashes and many other types of crashes relative to other intersections."
Read a summary Full copy, 1.7mb pdf - A 2003 Ontario Ministry of Transportation study found:
"Compared to the average number of reported collisions occurring in the before period, the average yearly number of reported collisions increased 15.1 per cent in the after period."
Read a summary Full copy, 1.5mb pdf - A 1995 Australian Road Research Board study found:
"The results of this study suggest that the installation of the RLC at these sites did not provide any reduction in accidents, rather there has been increases in rear end and adjacent approaches accidents on a before and after basis and also by comparison with the changes in accidents at intersection signals."
Read a summary Full copy, 2.4mb pdf - A 1995 Monash University (Australia) study found:
"a simple correlation analysis was undertaken for red light running data in the current study and revealed no significant relationship between the frequency of crashes at RLC and non-RLC sites and differences in red light running behaviour."
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The importance of the yellow warning signal time in reducing the instances of red light running is found in the following reports:
- A 2004 Texas Transportation Institute study found:
"An increase in yellow duration of 1.0 seconds is associated with a [crash frequency] of about 0.6, which corresponds to a 40 percent reduction in crashes."
Read a summary Full copy, 1.5mb pdf - A 2001 report by the Majority Leader of the U.S. House of Representatives found:
"The changes in the yellow signal timing regulations have resulted in the inadequate yellow times. And these inadequate yellow times are the likely cause of almost 80 percent of red light entries."
Full version with summary
