PM Depth Problem - Pavement Width from the Green Book

[blondebedhead]

31. Homework Problem ‐ A freeway ramp has the following characteristics:
Radius on inner edge of pavement equals 100 ft.
One‐lane, one‐way operation with no provisions for passing a stalled vehicle
Design traffic Condition A
Barrier curb on both sides


The ramp pavement width needed (ft) is most nearly:
(A) 15
(B) 16
© 17
(D) 18


SOLUTION:

Reference Table 3‐29, p 3‐103

Answer C

My question is barrier curb are same thing as vertical curb in terms of this problem and so I add 2 ft for the barrier curb?

Please don't make fun of me on this - I know the difference between barrier curb and vertical curb in real engineering world.

 

[ptatohed]

31. Homework Problem ‐ A freeway ramp has the following characteristics:

Radius on inner edge of pavement equals 100 ft.

One‐lane, one‐way operation with no provisions for passing a stalled vehicle

Design traffic Condition A

Barrier curb on both sides

The ramp pavement width needed (ft) is most nearly:

(A) 15

(B) 16

© 17

(D) 18

SOLUTION:

Reference Table 3‐29, p 3‐103

Answer C

My question is barrier curb are same thing as vertical curb in terms of this problem and so I add 2 ft for the barrier curb?

Please don't make fun of me on this - I know the difference between barrier curb and vertical curb in real engineering world.

I actually have no idea, even in the real world, what a 'barrier' curb or 'vertical' curb is! But I do know what a curb is. The point for this problem is that there are curbs (2). That's all you need to know. So, for Case I, condition A, R = 100', width = 15'. Then for Case I, with 2 curbs, add 2'. I believe the answer should be 17'?

 

[John QPE]

I agree.

15 ft + 2 ft = 17 ft

 

[JessieZ]

I am looking at the Table 3‐29. I am kind confused by the table set-up, it looks that adding 2 feet is not applicable for Condition A. That column seems like starting from Condition B.

 

[JessieZ]

Following up my previous comments, I am not sure if the columns in Table 3-29 are shifted a little bit, which is supposed to be aligned with each case, case I, ii, and III. Currently, in the table, Case I Condition A is aligned with the heading of this row. I am not sure if the authors did this on purpose or just a mistake. Does anyone have a clarification of this?

Thanks.

 

[zzzvvvzzz]

Following up my previous comments, I am not sure if the columns in Table 3-29 are shifted a little bit, which is supposed to be aligned with each case, case I, ii, and III. Currently, in the table, Case I Condition A is aligned with the heading of this row. I am not sure if the authors did this on purpose or just a mistake. Does anyone have a clarification of this?

Thanks.

 

[zzzvvvzzz]

Sorry about the double post... Trying to get the adding quote.

The column are for case 1-3 and the design traffic conditions are A-C within each case. Also believe C to be correct.

 

[JessieZ]

Sorry about the double post... Trying to get the adding quote.

The column are for case 1-3 and the design traffic conditions are A-C within each case. Also believe C to be correct.

Thank you for your help. so the table should shift to the left a little bit.

 

[ptatohed]

Sorry about the double post... Trying to get the adding quote.

The column are for case 1-3 and the design traffic conditions are A-C within each case. Also believe C to be correct.

Thank you for your help. so the table should shift to the left a little bit.

You are correct. For some reason, the table is not lined up properly. It used to be! Either in the previous (5th) edition, or the one before that (4th). Not sure why it got shifted for the 6th edition. See my first attachment to see my red-marks of how the columns of GDHS (6th Ed) Tbl 3-29 should be lined up, and see the second attachment to see how it used to be in previous editions (Source: http://sddot.com/business/design/docs/rd/rdmch12.pdf).

 

[John QPE]

Guys, please check the errata for the Green Book.

The column shifts were addressed in the 11/2013 Errata

 

[ptatohed]

Guys, please check the errata for the Green Book.

The column shifts were addressed in the 11/2013 Errata

Links JQ, links!

http://downloads.transportation.org/GDHS-6-Errata.pdf