Initial Maneuver Distance

Written by Jerry Ratzlaff on . Posted in Civil Engineering

sight distance 1Initial 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 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 \(\large{sec}\) \(\large{s}\)

 

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Tags: Transportation Equations