East TN Conservative

Article from thenewspaper.com

Key Statistic:
Further analysis indicated that the cameras are contributing to a definite increase in rear-end crashes, a possible decrease in angle crashes, a net decrease in injury crashes attributable to red light running, and an increase in total injury crashes. Page xiii

Summary of Empirical Bayes Method (Level 4 Analysis)

[Editor's note: only Fairfax County data reflects the most rigorous analysis. Other cities did not provide volume, yellow time, and data on other key factors.] The latter half of Appendix D shows the results of an Empirical Bayes analysis for Fairfax County crash data only. These results suggest the following:

• The cameras are correlated with an increase in total crashes of 8% to 17%.

• The cameras are correlated with an increase in rear-end crashes related to the presence of a red light; the increase ranges between 50% and 71%.

• The cameras are correlated with a decrease in crashes attributable to red light running, and the decrease is between 24% and 33%.

• The cameras are correlated with a decrease in injury crashes attributable to red light running, with the decrease being between 20% and 33%.

• The cameras are correlated with an increase in total injury crashes, with the increase being between 7% and 24%.