NCEES Material Transportation Afternoon session

[f1999587]

On the NCEES Material (sample problems Afternoon)

Could someone post the "solutions" for Problems 505 and 529 on the NCEES Material - Transportation (Afternoon Sample Problems).

Kindly help.

Thanks

Pavitra

 

[ptatohed]

On the NCEES Material (sample problems Afternoon)

Could someone post the "solutions" for Problems 505 and 529 on the NCEES Material - Transportation (Afternoon Sample Problems).

Kindly help.

Thanks

Pavitra

What year? 2011? You have the questions but not the solutions? If you do not own the NCEES Transpo Sample Q&Ss, you should buy it. https://account.ncees.org/exam-prep/store/category/PE/product/pe-civil-transportation-sample-questions-and-solutions

What is your specific question about the problems?

 

[f1999587]

For Problem 505, shouldn't the right answer be 7450 option C.

For Problem 529, given the improvements costs is same for all sites, the site selected should be based on the number of accidents, shouldn't the right answer be (B) for Site B?

Thanks.

 

[f1999587]

yes NCEES 2011

 

[ptatohed]

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

 

[f1999587]

u r awesome! Thanks.