Passing Sight Distance

Passing sight distance, abbreviated as PSD, is the total of all four formulas listed below.

 

Passing Sight Distance formula

\(\large{ PSD =  d_1 \;+\; d_2 \;+\; d_3 \;+\; d_4   }\)

Where:

\(\large{ PSD }\) = passing sight distance

\(\large{ d_1 }\) = initial maneuver distance

\(\large{ d_2 }\) = distance while passing vehicle occupies left lane

\(\large{ d_3 }\) = clearance length

\(\large{ d_4 }\) = distance traversed by opposing vehicle