Topics: Human Factors, Micro / Macroscopic Characteristics, SFD Relationships
1. Karl has run out of disposable contacts and cannot find his glasses one morning. A sign is placed on Route 66 so that drivers with 20/40 vision can read it from a distance of 150 feet. Karl's natural vision is 20/300 in both eyes (that is not a typo). If he is foolish enough to drive to campus that morning without his glasses, how close must he be to the sign in order to read it?
2. A volume of 1000 veh/hr is observed at an intersection approach. Find the peak flow rate within the hour for the following peak hour factors (PHF): 1.00, 0.90, 0.80, 0.40.
3. A traffic stream displays average vehicle headways of 2.4s at 50 mi/hr. Compute the density and rate of flow for this traffic stream.
4. A freeway detector records an occupancy of 0.26 for a 15-minute period. If the detector is 3.5 feet long, and the average vehicle has a length of 18 feet, what is the density implied by this measurement?
5. A lane on a freeway displays the following characteristics: (a) average headway between vehicles is 2.8s, and (b) the average spacing between vehicles is 235 feet. What is the rate of flow for the lane? What is the average speed in mi/hr?
6. From the following counts below, which were taken on a major arterial during the evening peak period, determine:
The peak hour
The peak hour volume
The peak flow rate within the peak hour
The peak hour factor (PHF)
|
Time Period
|
Volume (vehicles)
|
|
4:00 - 4:15 PM
|
450
|
|
4:15 - 4:30 PM
|
465
|
|
4:30 - 4:45 PM
|
490
|
|
4:45 - 5:00 PM
|
500
|
|
5:00 - 5:15 PM
|
503
|
|
5:15 - 5:30 PM
|
506
|
|
5:30 - 5:45 PM
|
460
|
|
5:45 - 6:00 PM
|
445
|
7. The following rows of data were sampled from a single lane of roadway
|
Density
(vplm)
|
SMS
(mph)
|
|
10
|
61.0
|
|
15
|
54.3
|
|
20
|
46.5
|
|
25
|
59.6
|
|
30
|
52.2
|
|
35
|
56.5
|
|
40
|
45.8
|
|
45
|
43.9
|
|
50
|
45.3
|
|
55
|
32.9
|
|
60
|
44.4
|
|
65
|
34.6
|
|
70
|
36.4
|
|
75
|
29.4
|
|
80
|
26.5
|
|
85
|
27.9
|
|
90
|
17.3
|
|
95
|
19.4
|
|
100
|
12.3
|
|
105
|
24.2
|
· Use Excel to plot the speed-density graph and use linear regression to fit a line to the data (include the chart in your submission).
· Estimate the free flow speed and clearly label on your Excel graph.
· Estimate the jam density and clearly label on your Excel graph.
· Estimate the maximum capacity for two lanes.
8. A study of freeway flow at a particular site has resulted in a calibrated speed-density relationship as follows: S = 57.5(1-0.008D). Determine the following:
Free Flow Speed
Speed at Capacity
Density at Capacity
Jam Density
Capacity