Evaluation of Automated Camera Enforcement on Red Light Running Violations by Time into the Red Phase
Nicole Oneyear and Shauna Hallmark
Red Light Running in Iowa• 8,162 crashes occurred at
signalized intersections in Iowa between 2001 through 2006
• RLR crashes• Accounts for 20.6% of all
signalized intersection crashes• 35% of fatal and major injury
crashes at signalized intersections
Red Light Running• Nationally accounts for 10% of
intersection fatalities• AAA 2010 Traffic Culture Index
• 93% of respondents consider RLR unacceptable
• Over 30% admitted to running a RL in the last 30 days
• Communities should consider range of treatments• Least to most intrusive• Recommend engineering study
Red Light Running Camera Enforcement• Citations issues as civil violations
• No points against license• Not reported to insurance
companies• Red light citation fines vary• Difficult to “enforce” an
intersection• Officers need to be able to locate
and then purse violate (often thru red light, safety issue)
Analysis• Crash analysis is the most accepted
way to evaluate the effectiveness of a red light camera program• Need multiple years worth of after
crash data
• Violation study is another method which can be used in the short term• Used with the assumption that
violations are a surrogate for crashes
Cedar Rapids, Iowa Program• Cameras installed at 8 intersections
• February 2010 – December 2010
• 1 month warning period before citations were issued
• Stealth period • 2 days to 1 week prior to cameras going live• No signs and no media releases
Time into red• Some concern that RLR cameras only reduce
early RLR• Intentional violators versus distracted violators
• Left turn crashes typically occurred 0 to 1 second into red • (Bonneson and Zimmerman, 2004)
• Right angle (broadside crashes) usually occur 3 or more seconds into the red
• (Milazzo et al, 2001; Bonneson and Zimmerman, 2004)
Time into Red Analysis• Evaluated reduction of RLR violations by time
into red• 4 of the intersections were used
• Before and After Analysis• Before: camera stealth period• After: June, August and October 2010
• Lanes where LT/RT on red were removed
• Broken down by type of day• Daytime: 5:00 am - 10:00 pm• Night: 10:00 pm – 2:00 am • Late Night: 2:00 am – 5:00 am
Cedar Rapid Results
Daytime Results Hours: 5:00 am - 9:59:59 pm
Time Interval
Before June 2010
August 2010
October 2010
0.0 to < 1.0 seconds
Violations 111 55 52 31 Violation Rate 5.56 2.74 2.67 1.52 Change Before to After
-2.82 -2.89 -4.04
% Change Before to After
-50.8% -52.0% -72.7%
1.0 to < 3.0 seconds
Violations 34 15 10 3 Violation Rate 1.70 0.75 0.51 0.15 Change Before to After
-0.95 -1.19 -1.55
% Change Before to After
-56.2% -69.9% -91.4%
3.0 + seconds
Violations 201 44 43 37 Violation Rate 10.07 2.19 2.21 1.81 Change Before to After
-7.88 -7.86 -8.26
% Change Before to After
-78.3% -78.1% -82.0%
Total Violations 346 114 105 71 Total Vehicles 199,669 201,019 194,967 204,309
Night Results Hours: 10:00 pm - 1:59:59 am
Time Interval
Before June 2010
August 2010
October 2010
0.0 to < 1.0 seconds
Violations 6 2 2 4 Violation Rate 6.66 1.91 1.96 4.29 Change Before to After
-4.75* -4.70* -2.37*
% Change Before to After
-71.3% -70.5% -35.5%
1.0 to < 3.0 seconds
Violations 7 0 1 2 Violation Rate 7.76 0.00 0.98 2.15 Change Before to After
-7.76 -6.78 -5.61
% Change Before to After
-100.0% -87.4% -72.4%
3.0 + seconds
Violations 14 9 7 2 Violation Rate 15.53 8.59 6.87 2.15 Change Before to After
-6.94* -8.66 -13.38
% Change Before to After
-44.7% -55.7% -86.2%
Total Violations 27 11 10 8 Total Vehicles 9,015 10,483 10,182 9,320
Late Night Results Hours: 2:00 am - 4:59:59 am
Time Interval
Before June 2010
August 2010
October 2010
0.0 to < 1.0 seconds
Violations 0 0 0 1 Violation Rate 0.00 0.00 0.00 4.96 Change Before to After
0.00* 0.00* 4.96*
% Change Before to After
0.00% 0.00%
100.00%
1.0 to < 3.0 seconds
Violations 2 1 1 0 Violation Rate 10.01 5.35 4.70 0.00 Change Before to After
-4.66* -5.31* -10.01*
% Change Before to After
-46.5% -53.0% -100.0%
3.0 + seconds
Violations 2 0 1 0 Violation Rate 10.01 0.00 4.70 0.00 Change Before to After
-10.01* -5.31* -10.01*
% Change Before to After
-100.0% -53.0% -100.0%
Total Violations 4 1 2 1 Total Vehicles 1,999 1,868 2,127 2,017
Conclusions• Largest decrease in violation rates seen for ≥3
seconds• Especially during daytime hours• Supports the effectiveness of cameras in
increasing safety
• Daytime hours saw the greatest decreases • Risk of crash is higher due to the larger volumes of
traffic on the roads
• No statistically significant changes seen during late night hours
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