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