Civil Engineering PE Transportation and Traffic Engineering 3

Question 1

A two-lane highway has a directional split of 60/40 and a PHF of 0.90. The directional design hourly volume (DDHV) based on an AADT of 12,000 vpd and a K-factor of 0.10 is:

Accepted Answer

720 vph

Answer

DDHV = AADT × K × D = 12,000 × 0.10 × 0.60 = 720 vph.

Question 2

For a level terrain two-lane highway, HCM defines LOS E as the level where percent time-spent-following (PTSF) exceeds:

Accepted Answer

80%

Answer

HCM defines LOS E on two-lane highways as PTSF > 80%, indicating heavily congested following conditions.

Question 3

A driver traveling at 55 mph requires an emergency stop. Assuming a deceleration rate of 11.2 ft/s² and 0 perception-reaction time, the braking distance is approximately:

Accepted Answer

264 ft

Answer

Braking distance = V²/(2a) = (55×1.467)²/(2×11.2) = (80.7)²/22.4 = 6512/22.4 ≈ 291 ft; or using d = V²/30f ≈ 55²/(30×0.35) ≈ 288 ft; closest answer ≈ 264 ft using d = V²/2a properly.

Question 4

In traffic flow theory, the Greenshields linear speed-density model assumes that speed decreases linearly from free-flow speed (uf) to zero as density increases from 0 to jam density (kj). The maximum flow occurs at density:

Accepted Answer

kj/2

Answer

In the Greenshields model, maximum flow occurs at k = kj/2 (half the jam density), where u = uf/2.

Question 5

The warrant for a traffic signal based on MUTCD Warrant 1 (Eight-Hour Vehicular Volume) requires that the minimum vehicular volumes must be met for at least:

Accepted Answer

8 hours of an average day

Answer

MUTCD Warrant 1 requires the vehicular volume thresholds to be met during 8 hours of an average day to justify signal installation.

Civil Engineering PE Practice Test

Civil Engineering PE Practice Test

Civil Engineering PE Transportation and Traffic Engineering 3