Civil Engineering PE Transportation and Traffic Engineering 5

Question 1

A freeway weaving section has a weaving volume of 1,200 vph and a non-weaving volume of 3,000 vph. The volume ratio (VR) used in HCM weaving analysis is:

Accepted Answer

0.286

Answer

VR = weaving volume / total volume = 1,200/(1,200+3,000) = 1,200/4,200 ≈ 0.286.

Question 2

A highway curve has a posted advisory speed of 35 mph. A truck with a center of gravity height of 6 ft and track width of 8 ft negotiates the curve. The rollover threshold lateral acceleration is:

Accepted Answer

0.67g

Answer

Rollover threshold = track width/(2 × CG height) = 8/(2×6) = 0.667g ≈ 0.67g.

Question 3

The MUTCD requires that a 'School Speed Limit' sign be used only when the speed limit applies during specific times. Which beacon type is typically used with school speed limit assemblies?

Accepted Answer

Flashing yellow LED beacon

Answer

MUTCD recommends flashing yellow LED beacons with school speed limit signs to alert drivers when the reduced speed is in effect.

Question 4

The AASHTO flexible pavement design uses the Structural Number (SN). If layer coefficients are a1=0.44, a2=0.14, a3=0.11, drainage coefficients m2=m3=1.0, and layer thicknesses D1=4 in, D2=6 in, D3=8 in, the SN is:

Accepted Answer

3.48

Answer

SN = a1D1 + a2D2m2 + a3D3m3 = 0.44×4 + 0.14×6×1.0 + 0.11×8×1.0 = 1.76 + 0.84 + 0.88 = 3.48.

Question 5

Speed studies on a road yield the following 85th percentile speed: 52 mph. The posted limit is 45 mph. Based on the 85th percentile rule, the engineer would recommend:

Accepted Answer

Raising the speed limit to 50 mph

Answer

The 85th percentile rule suggests setting the speed limit near the 85th percentile speed; 52 mph rounds to 50 mph per standard practice.

Civil Engineering PE Practice Test

Civil Engineering PE Practice Test

Civil Engineering PE Transportation and Traffic Engineering 5