BCE Highway 4 — Questions and Answers
Question 1: What is the primary function of a weigh-in-motion (WIM) system installed on a highway?
- Enforce speed limits dynamically
- Measure vehicle axle loads without stopping trucks (Correct answer)
- Count pedestrian crossings
- Monitor pavement temperature
Correct answer: Measure vehicle axle loads without stopping trucks
WIM systems use embedded sensors to measure dynamic axle loads as vehicles travel at normal speeds, collecting load data for pavement design and enforcement.
Question 2: A vertical sag curve is designed for which primary criterion when located outside of a sag?
- Stopping sight distance
- Headlight sight distance (Correct answer)
- Passing sight distance
- Decision sight distance
Correct answer: Headlight sight distance
Sag curves at night must be long enough so headlight beams illuminate sufficient stopping distance ahead, making headlight sight distance the controlling criterion.
Question 3: Which pavement rehabilitation technique involves removing and replacing only the top layer of an existing asphalt pavement?
- Full-depth reclamation
- Mill and overlay (Correct answer)
- Crack sealing
- Slurry seal
Correct answer: Mill and overlay
Mill and overlay grinds off the deteriorated surface layer and places a new hot-mix asphalt overlay, restoring ride quality and surface friction.
Question 4: The stopping sight distance (SSD) on a highway is composed of which two distance components?
- Perception-reaction distance and braking distance (Correct answer)
- Decision distance and maneuver distance
- Preview distance and curve radius
- Gap acceptance distance and merge distance
Correct answer: Perception-reaction distance and braking distance
SSD equals the distance traveled during perception-reaction time (typically 2.5 s) plus the braking distance to a complete stop.
Question 5: In geometric design, what is the 'K-value' used to characterize a vertical curve?
- Ratio of curve length to algebraic grade difference (Correct answer)
- Number of lanes divided by curve radius
- Design speed squared divided by 100
- Superelevation rate times curve length
Correct answer: Ratio of curve length to algebraic grade difference
K = L/|A| where L is curve length and A is the absolute algebraic difference in grades; it simplifies sight distance calculations for crest and sag curves.
Question 6: Which type of intersection control is most appropriate for a high-volume urban intersection with multiple conflicting movements and complex geometry?
- Two-way stop control
- All-way stop control
- Roundabout
- Signalized intersection (Correct answer)
Correct answer: Signalized intersection
Signalized intersections with phase timing plans are best suited for high-volume, complex urban intersections to maximize throughput and manage conflicting movements.
Question 7: What is 'rut depth' in flexible pavement distress, and what structural failure mechanism does it indicate?
- Surface cracking from oxidation, indicating binder aging
- Permanent longitudinal deformation in wheel paths, indicating shear failure in pavement or subgrade (Correct answer)
- Transverse thermal cracking, indicating low-temperature brittleness
- Edge deterioration from frost heave
Correct answer: Permanent longitudinal deformation in wheel paths, indicating shear failure in pavement or subgrade
Rutting is permanent deformation (depression) along wheel tracks caused by repeated shear stress exceeding the strength of asphalt layers or subgrade.
BCE Highway 4
What is the primary function of a weigh-in-motion (WIM) system installed on a highway?