Table 20: Crashes at Red Light Camera Intersections Since Installation Controlling for Exposure

The observed count of crashes in the before period, the observed number of crashes in the after period for all approaches at the Red Light Camera intersections and the monitored approaches. The table also provides the monthly average crashes in the before and after periods and the average difference. A positive average difference indicates an increase in the average crashes from the pre to post time period and a negative difference indicates a decrease in the average number of crashes from the pre to post time periods.

Table 20. Crashes at Red Light Camera Intersections Before and After Controlling for Exposure

 

Pre-Count

Post-Count

Count Increase / Decrease

Percent Increase / Decrease

After RLC  Monthly Average

Before RLC  Monthly Average

Difference

All Approaches

Total Crashes

1740

1769

+19

+1.1

3.37

3.34

0.03

Injury Crashes

579

459

-120

-26.1

0.88

1.11

***-0.23

PDO Crashes

1161

1308

+147

+12.7

2.50

2.23

** 0.27

Rear End Crashes

1256

1386

+130

+10.4

2.65

2.41

* 0.24

Angle Crashes

328

213

-115

-54.0

0.41

0.63

***-0.22

Monitored Approaches

Total Crashes

951

1,000

+49

+5.2

2.30

2.18

0.12

Injury Crashes

329

270

-59

-21.9

0.62

0.75

* -0.13

PDO Crashes

622

729

+107

+17.2

1.68

1.42

*** 0.26

Rear End Crashes

716

814

+98

+13.7

1.88

1.64

* 0.24

Angle Crashes

164

103

-61

-59.2

0.43

0.54

* -0.11

Note: #p<0.10, *p<0.05, **p<0.01, ***p<0.001