Question

A driver counts 21 other vehicles using 3 EB lanes on one section of I-80 between her rented car and an overpass ahead. It turned out to be 0.78 mile to the overpass from the point at which she started her vehicle count. The vehicles were moving at approximately 52 mph at the time. Traffic was distributed evenly over the three EB lanes.
Required:
a. Calculate the vehicle density per lane (excluding the driver's rental vehicle) on that stretch of EB I-80.
b. What was the flow rate for that section of I-80?

Answer 1

Answer:

vehicle density =  28.205 veh/mile

flow rate =  0.909 veh/hr

Explanation:

given data

count n = 21

distance = 0.78 miles

speed = 52 mph

solution

we get here vehicle density that is express as

vehicle density = n ÷ distance    ...............1

vehicle density = ( 21 + 1 )  ÷ 0.78

vehicle density  k =  28.205 veh/mile

and

now we get here flow rate that is express as

flow rate = k × vs    .................2

flow rate = 28.205 × ( 52 × 0.00062 ÷ 1m )

flow rate =  0.909 veh/hr