Initial Maneuver Distance

Initial maneuver distance, abbreviated as \(d_1\), is the distance traversed during the perception and reaction time and during the initial acceleration to the point of encroachment on the left lane.

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

 

Initial Maneuver Distance formulas

\(\large{ d_1 =  \frac{ t_1  }{ 0.68 } \; \left(  \bar {u} \;-\; m \;+\; \frac{ \bar {a} \; t_1 }{ 2 }  \right)   }\)
\(\large{ d_1 =  1.47 \; t_1 \; \left(  \bar {u} \;-\; m \;+\; \frac{ \bar {a} \; t_1 }{ 2 }  \right)   }\)

Where:

Units	English	Metric
\(\large{ d_1 }\) = initial maneuver distance	\(\large{ft}\)	\(\large{m}\)
\(\large{ \bar {a} }\) = average acceleration	\(\large{\frac{ft}{sec^2}}\)	\(\large{\frac{m}{s^2}}\)
\(\large{ \bar {u} }\) = average speed of passing vehicle	\(\large{\frac{ft}{sec}}\)	\(\large{\frac{m}{s}}\)
\(\large{ m }\) = difference in speed of passing vehicle and passing vehicle	\(\large{\frac{ft}{sec}}\)	\(\large{\frac{m}{s}}\)
\(\large{ t_1 }\) = time of initial maneuver	\(\large{sec}\)	\(\large{s}\)