Which of the following is an acceptable control measure for unpaved haul/access roads?

• A. Planting grass
• B. Applying gravel
• C. Limit to 40 trips per day
• D. Using only chemical dust suppressants

Answer: (B)

Applying gravel to unpaved haul and access roads is an effective control measure for dust management. Gravel serves multiple purposes; it can enhance the surface stability of the road, reduce dust emissions by forming a solid base, and help with drainage. The presence of gravel can minimize the erosion of the road's surface, which is a primary source of dust. By maintaining a well-graded and compacted gravel surface, the amount of airborne particulate matter generated by vehicle traffic can be significantly reduced.

Other options may have varying effectiveness or limitations. For instance, while planting grass can help with soil stabilization and may reduce dust in the long term, it requires maintenance and may take time to establish. Limiting the number of trips is a management strategy that can reduce dust; however, it does not physically control dust generation during the trips that do occur. Using only chemical dust suppressants can effectively reduce dust but may not provide a long-term solution and could have environmental or health considerations that need to be managed. Thus, applying gravel stands out as a practical and immediately effective measure for controlling dust on unpaved roads.