Using the HSM Empirical Bayes method, conduct an evaluation to determine if the

countermeasures installed at the test site were effective in reducing crashes at $95\%$

level of confidence. Specifically

a$.$ Show your work for all $12$ steps presented in class for the HSM EB Method.

Label your work step by step.

b$.$ State the unbiased CMF and Safety Effectiveness, and their Variances

c$.$ Comment on its statistical significance

d$.$ Determine the confidence interval on the unbiased CMF

Hint: Use average annual values for the before and after periods $($crashes$,$ ADTs,

proportions$)$

Regression model:

$P=4\mathrm{.}72{10}^{-10}(AD{T}_{intersection}{)}^{2\mathrm{.}278}(AD{T}_{\text{P}\text{r}\text{o}\text{p}\text{o}\text{r}\text{t}\text{i}\text{o}\text{n}}{)}^{-0\mathrm{.}866}$

$AD{T}_{intersection}=$ Annual Daily Traffic $at$ Intersection

$AD{T}_{\text{p}\text{r}\text{o}\text{p}\text{o}\text{r}\text{t}\text{i}\text{n}}=$ Ratio $of$ minor street ADT and ADT $of$ intersection

$k=4\mathrm{.}0$

$AD{T}_{intersection}=$ Annual Daily Traffic at Intersection

$AD{T}_{\text{p}\text{r}\text{o}\text{p}\text{o}\text{r}\text{t}\text{i}\text{n}}=$ Ratio of minor street ADT and ADT of intersection

A safety program was implemented which focused on installing countermeasures to

reduce right$-$angle crashes at $8$ test intersections. Using the chi$-$square test, determine

if the safety program was effective. Use $95\%$ LOC.