Ramp Pavement Width needed (AASHTO GHDS 2011)

[JMT]

I am trying to solve a problem in the NCEES Transportation Afternoon Sample Questions. It says:

A freeway ramp has the following characteristics:

-Radius on inner edge of pavement =100'

-1-lane, 1-way operation w/ no provision 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

C) 17

D) 18

The solution references GDHS 2004, p. 839, Ex. 10-67

Width = 15' +2' (for vertical curb on both sides) = 17'

*I can't seem to find a table or equation in GDHS 2011 that would help to solve a question like this. Thanks for your help!

 

[ptatohed]

I am trying to solve a problem in the NCEES Transportation Afternoon Sample Questions. It says:

A freeway ramp has the following characteristics:

-Radius on inner edge of pavement =100'

-1-lane, 1-way operation w/ no provision 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

C) 17

D) 18

The solution references GDHS 2004, p. 839, Ex. 10-67

Width = 15' +2' (for vertical curb on both sides) = 17'

*I can't seem to find a table or equation in GDHS 2011 that would help to solve a question like this. Thanks for your help!

J, the answer can be found in the GDHS 6th Ed on page 3-103, Table 3-29. With R = 100', Case I (no passing) and Traffic Condition A, you'll see the Pavement Width is 15'. Then on the bottom half of the table under Width Modifications, add 2' for two vertical curbs. You can read more too on page 10-102 (Ramp traveled-way widths).

 

[JMT]

Thanks for the help Ptatohed!

 

[MWC PE]

This is one of the edits to the 2011 Green Book that I didn't like. Table 3-29 used to be in chapter 10 with ramp design where it makes more sense. They moved to geometric design section which I guess makes organizational sense but practical I liked it better in in chapter 10 since that is where all other ramp information is provided. Oh well my 2 cents.