Analysis of Setback Distance on Curves 

Good explanation with neat sketches sir...thank you so much sir

Very nicely tought

And for rational formula STBD = 1/ RAD + RAD( sin ANG of SIGHT)

Think SBD depends on speed also, as Speed influence SSD.

Good explanation..then i think we can or should rewrite the formula as STB = 8 * RAD / SD * SD

Setback distance = R(1 -cosa/2) Or, Setback distance = R - (R-d)cosa/2 = R(1-Cosa/2) + d cosa/2 Or, Setback distance = R- (R-d)cosa/2 +(S-Lc)(Sina/2)/2 = R(1-Cosa/2) + d cosa/2+ (S-Lc)(Sina/2)/2 Clearly Setback distance is directly proportional to R So, set back distance increase with decrease in radius, how??

And for multi lane roads STBD = 1/ RAD + RAD + DST sin Ang of sight / 2