# Initial Maneuver Distance

on . Posted in Civil Engineering

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.

### Initial Maneuver Distance formula

$$d_1 = ( t_1 \;/\; 0.68 ) \; ( \bar {u} - m + ( \bar {a} \; t_1 \;/\; 2 ) \; )$$
Symbol English Metric
$$d_1$$ = initial maneuver distance  $$ft$$ $$m$$
$$t_1$$ = time of initial maneuver $$sec$$ $$s$$
$$\bar {u}$$ = average speed of passing vehicle $$ft\;/\;sec$$ $$m\;/\;s$$
$$m$$ = difference in speed of passing vehicle and passing vehicle $$ft\;/\;sec$$ $$m\;/\;s$$
$$\bar {a}$$ = average acceleration $$ft\;/\;sec^2$$ $$m\;/\;s^2$$

### Initial Maneuver Distance formulas

$$d_1 = 1.47 \; t_1 \; ( \bar {u} - m + ( \bar {a} \; t_1 \;/\; 2 ) \; )$$
Symbol English Metric
$$d_1$$ = initial maneuver distance  $$ft$$ $$m$$
$$t_1$$ = time of initial maneuver $$sec$$ $$s$$
$$\bar {u}$$ = average speed of passing vehicle $$ft\;/\;sec$$ $$m\;/\;s$$
$$m$$ = difference in speed of passing vehicle and passing vehicle $$ft\;/\;sec$$ $$m\;/\;s$$
$$\bar {a}$$ = average acceleration $$ft\;/\;sec^2$$ $$m\;/\;s^2$$