Mile Marker

Sample Size

Mean Speed

(MPH)

Standard Deviation

(MPH)

p-value

Significant reduction in mean speeds

Before

After

Before

After

Before

After

147.0 - 146.9

11,946

11,729

71.97

72.46

7.67

6.68

1.000

-

146.9 - 146.8

12,036

11,764

72.16

72.39

7.43

6.82

0.995

-

146.8 - 146.7

11,983

11,747

72.35

72.43

7.36

7.03

0.792

-

146.7 - 146.6

11,944

11,833

72.22

72.09

7.59

7.36

0.09

-

146.6 - 146.5

11,988

11,770

72.26

72.26

7.37

7.09

0.515

-

146.5 - 146.4

11,928

11,716

72.38

72.64

7.42

6.70

0.998

-

146.4 - 146.3

11,986

11,748

72.01

72.41

7.72

6.72

0.999

-

146.3 - 146.2

12,033

11,814

71.55

72.10

8.33

7.18

1.000

-

146.2 - 146.1

11,923

11,636

71.20

71.55

9.04

7.79

0.999

-

146.1 - 146.0

11,029

10,774

71.91

71.77

8.78

7.36

0.093

-

146.0 - 145.9

11,015

10,956

71.83

70.37

8.59

7.85

<0.001

Yes

145.9 - 145.8

11,035

11,340

71.66

68.46

8.77

8.16

<0.001

Yes

145.8 - 145.7*

11,122

11,380

71.49

67.70

8.89

8.26

<0.001

Yes

145.7 - 145.6

11,945

12,147

70.66

67.27

9.57

8.59

<0.001

Yes

145.6 - 145.5

11,894

12,062

70.65

67.64

9.83

8.76

<0.001

Yes

145.5 - 145.4

12,038

11,988

69.96

67.32

10.52

9.29

<0.001

Yes

145.4 - 145.3

12,005

11,925

69.82

67.39

10.21

9.41

<0.001

Yes

145.3 - 145.2

11,939

11,842

70.17

67.72

9.99

9.51

<0.001

Yes

145.2 - 145.1

11,855

11,667

70.30

67.92

10.07

9.61

<0.001

Yes

145.1 - 145.0

11,684

11,546

70.65

68.38

9.79

9.46

<0.001

Yes