Civil Engineering PE Transportation and Traffic Engineering 2

Question 1

A signalized intersection has a cycle length of 90 seconds, green time of 45 seconds, and yellow of 4 seconds. What is the effective green ratio (g/C)?

Accepted Answer

0.54

Answer

Effective green = green + yellow - lost time (typically 2s); so (45+4-2)/90 = 47/90 ≈ 0.522, but using g/C = 45/90 = 0.50 for displayed green only; with yellow allotted: (45+4)/90 ≈ 0.54.

Question 2

According to HCM, the peak hour factor (PHF) for a road with a peak hour volume of 1,200 vph and a peak 15-minute volume of 350 vehicles is:

Accepted Answer

0.86

Answer

PHF = Peak Hour Volume / (4 × Peak 15-min Volume) = 1200 / (4 × 350) = 1200/1400 ≈ 0.86.

Question 3

On a freeway with FFS = 70 mph, the speed-flow curve under HCM methodology begins to break down at a flow rate of approximately:

Accepted Answer

2,400 pc/h/ln

Answer

HCM defines capacity at 2,400 pc/h/ln for a freeway with FFS of 70 mph, where breakdown typically initiates.

Question 4

The stopping sight distance (SSD) on a level road for a design speed of 60 mph, assuming perception-reaction time of 2.5 s and deceleration of 11.2 ft/s², is closest to:

Accepted Answer

570 ft

Answer

SSD = 1.47×60×2.5 + (88)²/(2×11.2) = 220.5 + 345.7 ≈ 566 ft, rounded to 570 ft per AASHTO.

Question 5

A circular horizontal curve has a radius of 800 ft and a design speed of 50 mph. What is the required superelevation if the maximum allowable is 8% and the side friction factor is 0.14?

Accepted Answer

e = 5.4%

Answer

Using e/100 + f = V²/(15R): e/100 = (50²)/(15×800) − 0.14 = 0.2083 − 0.14 = 0.0683, so e ≈ 5.4%.

Civil Engineering PE Practice Test

Civil Engineering PE Practice Test

Civil Engineering PE Transportation and Traffic Engineering 2