Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations SDETERS on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

profile grade break instead of vertical curve

Status
Not open for further replies.

kailiwalker

Civil/Environmental
Oct 20, 2010
1
Do anyone know where to find guidance on roadway profile grade breaks. It seems everyone i talk to has a different answer. I have a roadway with a design speed of 35 mph with a 100' sag curve. i want to get rid of the sag curve and replace it with a grade break but not sure if an AD value of 1.5% is Ok
 
Replies continue below

Recommended for you

The number I've heard is 1% maximum on a grade break.
Why not use a shorter curve length, say 20' to 40'.


Some discussion at thread194-174877
 
Generally, a maximum vertical grade break without vertical curve is limited to the 0.5%-1.0% range. For instance, for a rural gravel road 1% may be allowable, but for a paved highway the limit is probably 0.5%. The design speed and surface material are the two main factors that are considered in these requirements.
 
If it's a public road you should check local regulations. In these parts a vertical curve is required on public roads if the algebraic difference is 1% or more.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor