On a paved, two-lane road, sand and gravel are most likely to collect:
Answers
In the left wheel track.
Near the center of the road.
Near the sides of the road.
In the center of each lane.
The correct answer and explanation is:
The correct answer is Near the sides of the road.
Explanation:
On a paved, two-lane road, sand and gravel are most likely to accumulate near the edges or shoulders of the road for several reasons related to traffic flow, road design, and the nature of road maintenance.
- Road Design and Drainage:
- Roads are generally designed with a slight slope (camber) toward the edges, which facilitates water drainage. This slope helps direct rainwater and debris toward the road’s shoulders. As rainwater runs off, it can carry sand, gravel, and other small debris from the road surface, which eventually collects along the edges, especially after storms or heavy traffic.
- Traffic Dynamics:
- Most vehicles tend to travel within the main part of the lanes, with less frequent movement near the edges. Over time, the edges of the road experience less tire pressure compared to the center of the lane, causing debris like sand and gravel to accumulate. In contrast, the more frequently used tire tracks in the center of each lane are subject to constant compaction, preventing the buildup of debris in those areas.
- Low Traffic Areas:
- Areas near the road’s edges, where vehicles rarely travel, often gather more loose material because there is less disturbance to these regions. Gravel and sand are swept from the center of the lanes by tire movement and are deposited along the outer edges. This is especially true on roads with low traffic, where the tires may not disturb the edges as much.
- Maintenance Activities:
- Road maintenance equipment, such as sweepers, is designed to remove debris from the central part of the roadway. However, these machines may leave behind sand and gravel in the shoulder area. Also, during winter conditions or construction projects, sand and gravel used for traction or roadwork can accumulate on the edges, especially where vehicles frequently park or slow down.
Thus, sand and gravel are more likely to collect near the sides of the road, where they are less disturbed by traffic but are still affected by drainage and maintenance.