Anti RLC site www.stpetecameras.org:  Walden TTI study:  BIAS in the "study" is pretty clear!

- The bias in the study is pretty clear

- They focus mostly on RLR(red light related) crashes instead of total crashes

- The total crash reduction using their stats is 10.4%

- The Houston numbers are suspect since they are vastly different from previous reports using the same time period

- They omitted Lubbock again, as well as 2 other communities that removed their RLCs

- They completely ignore the changing traffic volumes from 2005-2007 and 2008-2010

- They mention yellow signal times and all-red intervals, but make no mention of changes in these over the study period

- All crashes below $1000 in damage are excluded

- 26.5% of officer-coded intersection-related crashes were removed from the study data because they were deemed not really intersection-related by the researchers

- The opening figure of "1000 fatalities" due to red light running is taken from a FHWA 2008 report, instead of the 762 figure from the NHSTA report from the same year, or the more recent figure of just over 800 from a FHWA 2010 report.
 

- There are no control intersections to compare the RLC changes to

- It is interesting that they gathered data on fatal crashes, but made no mention of an increase or decrease in fatal crashes, I would love to see the raw data on that.
 

Since they used no control intersections or measures of traffic volume, this report is pretty useless and invalidates their conclusions because there is no frame of reference for the crash percent changes they mention.
 

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