# Passing Sight Distance

Written by Jerry Ratzlaff on . Posted in Civil Engineering

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:

 Units English Metric $$\large{ PSD }$$ = passing sight distance $$\large{ft}$$ $$\large{m}$$ $$\large{ d_1 }$$ = initial maneuver distance $$\large{ft}$$ $$\large{m}$$ $$\large{ d_2 }$$ = distance while passing vehicle occupies left lane $$\large{ft}$$ $$\large{m}$$ $$\large{ d_3 }$$ = clearance length $$\large{ft}$$ $$\large{m}$$ $$\large{ d_4 }$$ = distance traversed by opposing vehicle $$\large{ft}$$ $$\large{m}$$