NYSDOT Stopping Sight Distance - Profile Label Expressions

[Avera737]

Can anyone assist me with editing the following expression:

IF({Profile Curve Length}>=(((2159*{Profile Curve Length})/{Grade Change})^(1/2)),(((2159*{Profile Curve Length})/{Grade Change})^(1/2)),((1079/{Grade Change})+({Profile Curve Length}/2)))

The goal of the expression is to calculate stopping sight distance which is dictated by the two following equations:

S<L: S=((658*L)/A)^1/2

and

S>L: S=(329/A)+(L/2)

Where:

S = Stopping Sight Distance

A = Algebraic Difference Between Grades

L = Curve Length

(The formula is in meters, however my expression converts the two constants to feet.)

I am not getting any results with the expression right now.  It's not returning any value as far as I can tell.  Any help would be greatly appreciated.

[Jeff_M · Accepted solution]

A few years ago I found that using {Grade Change} in a formula will break it. It may still be the case.

Have a look HERE to see if it helps.

[Avera737]

Alright, thanks for the tip.  I'll give it a shot.

[Avera737]

Thank you Jeff!

That seems to be the issue... for future reference when you call out {Grade In}-{Grade Out} you'll need to multiply the result by 100 for use in the formula.