Consider a 1mile study segment consisting of a single lane w

Consider a 1-mile study segment consisting of a single lane where the prevailing flow is 800 veh/h, the prevailing speed is 60 mph, and average vehicle length is 19 feet. There are two (2) loop detectors buried in the pavement. The first loop located at 1/3-mile happens to have an effective length of 14 feet. The second loop located at 2/3-mile happens to have an effective length of 7 feet. Comparo-tho-lame-eeoupanay meacuremente-ao-reported-by the twe-different leops What\'s the apparent PRECENT occupancy reported by the 14-ft loop?

Solution

Given data:

distance=1 mile

flow=800 veh/hr

speed=60 mph

length=19 feet

step 2:

Effective length of 1st loop=1/3rd mile

effective length=14 feet

step 3:

The specimen speed of the sample is given by

S=N/(TOg)

N= number of vehicles

T=observation interval

g=40.9/6.55 (g is called as the correction factor) and 6.55 is the average vehicle length in m.

step 4:

convert the given system to SI units

N=800

Length of vehicle=19 feet=5.79 m

speed of vehicle=70 miles per hour

=60x1.66 kmph

=60x1.66x5/18

=26.8224 m/sec

step 4:

for a loop of 14 feet length

length=4.26 m

S=EVL/t₀

EVL= length of vehicle+length of loop

26.82=5.79+4.26/t₀

t₀=0.374

hence the occupany percentage is 37.4%