This is how I solved them (a little differently than NCEES's solutions).
505.
No, the answer can't be C because that's the Daily volume for just Wednesday. The question asks for the weekly ADT. This is a simple proportions problem. They give you 7 day's worth of daily volumes for Street A, tell you that Street A and B are similar and then give you Street B's Wednesday daily volume. So, the ratio is:
(Wed Daily Volume A) / (Weekly Average ADT A) = (Wed Daily Volume B) / (Weekly Average ADT B)
We know three out of the four variables, right?
If you sum up all of Street A's daily volumes and divide by 7, you get a weekly average ADT of 9084.3. So:
10,300 / 9084.3 = 7450 / (Weekly Average ADT B); (Weekly Average ADT B) = 6570.67
Answer A
529.
No, you can't simply say that the site with the highest number of accidents is the best site to improve. It's not just the highest number of accidents - to get the best bang for the buck, you need to calculate the highest number of accidents per vehicle mile. As an example, let's say a 100 mile stretch of roadway with an ADT of 20,000 has an annual accident count of 10. Now take a 20 mile roadway with an ADT of 5,000 and an accident count of 5. Well, even though the 100 mile segment has more total accidents, the 20 mile segment has a lot more accidents per vehicle per mile. Does that make sense?
I solved this problem differently than NCEES. I think their method is unnecessarily long. I simply took the # of accidents per mile per ADT.
Site A: 12 / 5.2 / 6100 = .000378
Site B: 15 / 10.0 / 7500 = .000198
Site C: 8 / 6.3 / 5200 = .000244
Site D: 10 / 8.4 / 6900 = .000173
The highest accident rate is Site A and, thus, Site A should receive the improvement funds.
Answer A