Practice Question: Space Mean Speed Based on Traffic Density

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Solution

Answer: A) 15 mph

Space mean speed can be determined based on free flow speed, density, and jam density.
\[u_s=u_f (1-\frac{k}{k_j} )\]
Free flow speed (miles per hour):
\[u_f  =50 \ mph\]
Density (vehicles per mile):
\[k=350 \ vpm\]
Jam Density (vehicles per mile):
\[k_j=500 \ vpm\]
Calculate space mean speed:
\[u_s=50 \ mph*(1- \frac{350 \ vpm}{500 \ vpm})=15 \ mph\]
 

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